Auto merge of #56042 - petrochenkov:nuni, r=petrochenkov

[nightly] resolve: Implement uniform paths 2.0

Forward-port of https://github.com/rust-lang/rust/pull/55884 to nightly.

r? @ghost

171 files changed, 1203 insertions, 613 deletions

diff --git a/src/test/ui-fulldeps/custom-derive/derive-in-mod.rs b/src/test/ui-fulldeps/custom-derive/derive-in-mod.rs
new file mode 100644
index 00000000000..8478ff1a6ae
--- /dev/null
+++ b/src/test/ui-fulldeps/custom-derive/derive-in-mod.rs
@@ -0,0 +1,13 @@
+// compile-pass
+// aux-build:plugin.rs
+
+extern crate plugin;
+
+mod inner {
+    use plugin::WithHelper;
+
+    #[derive(WithHelper)]
+    struct S;
+}
+
+fn main() {}
diff --git a/src/test/ui-fulldeps/custom-derive/helper-attr-blocked-by-import-ambig.stderr b/src/test/ui-fulldeps/custom-derive/helper-attr-blocked-by-import-ambig.stderr
index 059629c0b62..ee98873064f 100644
--- a/src/test/ui-fulldeps/custom-derive/helper-attr-blocked-by-import-ambig.stderr
+++ b/src/test/ui-fulldeps/custom-derive/helper-attr-blocked-by-import-ambig.stderr
@@ -1,19 +1,20 @@
-error[E0659]: `helper` is ambiguous
+error[E0659]: `helper` is ambiguous (derive helper attribute vs any other name)
   --> $DIR/helper-attr-blocked-by-import-ambig.rs:10:3
    |
 LL | #[helper] //~ ERROR `helper` is ambiguous
    |   ^^^^^^ ambiguous name
    |
-note: `helper` could refer to the name defined here
+note: `helper` could refer to the derive helper attribute defined here
   --> $DIR/helper-attr-blocked-by-import-ambig.rs:9:10
    |
 LL | #[derive(WithHelper)]
    |          ^^^^^^^^^^
-note: `helper` could also refer to the name imported here
+note: `helper` could also refer to the attribute macro imported here
   --> $DIR/helper-attr-blocked-by-import-ambig.rs:7:5
    |
 LL | use plugin::helper;
    |     ^^^^^^^^^^^^^^
+   = help: use `self::helper` to refer to this attribute macro unambiguously
 
 error: aborting due to previous error
 
diff --git a/src/test/ui-fulldeps/proc-macro/ambiguous-builtin-attrs.stderr b/src/test/ui-fulldeps/proc-macro/ambiguous-builtin-attrs.stderr
index ea867faf47b..34b21ea2683 100644
--- a/src/test/ui-fulldeps/proc-macro/ambiguous-builtin-attrs.stderr
+++ b/src/test/ui-fulldeps/proc-macro/ambiguous-builtin-attrs.stderr
@@ -1,98 +1,78 @@
-error[E0659]: `repr` is ambiguous
+error[E0425]: cannot find value `NonExistent` in this scope
+  --> $DIR/ambiguous-builtin-attrs.rs:30:5
+   |
+LL |     NonExistent; //~ ERROR cannot find value `NonExistent` in this scope
+   |     ^^^^^^^^^^^ not found in this scope
+
+error[E0659]: `repr` is ambiguous (built-in attribute vs any other name)
   --> $DIR/ambiguous-builtin-attrs.rs:9:3
    |
 LL | #[repr(C)] //~ ERROR `repr` is ambiguous
    |   ^^^^ ambiguous name
    |
-note: `repr` could refer to the name imported here
+   = note: `repr` could refer to a built-in attribute
+note: `repr` could also refer to the attribute macro imported here
   --> $DIR/ambiguous-builtin-attrs.rs:7:5
    |
 LL | use builtin_attrs::*;
    |     ^^^^^^^^^^^^^^^^
-note: `repr` could also refer to the name defined here
-  --> $DIR/ambiguous-builtin-attrs.rs:9:3
-   |
-LL | #[repr(C)] //~ ERROR `repr` is ambiguous
-   |   ^^^^
-   = note: consider adding an explicit import of `repr` to disambiguate
+   = help: use `self::repr` to refer to this attribute macro unambiguously
 
-error[E0659]: `repr` is ambiguous
+error[E0659]: `repr` is ambiguous (built-in attribute vs any other name)
   --> $DIR/ambiguous-builtin-attrs.rs:11:19
    |
 LL | #[cfg_attr(all(), repr(C))] //~ ERROR `repr` is ambiguous
    |                   ^^^^ ambiguous name
    |
-note: `repr` could refer to the name imported here
+   = note: `repr` could refer to a built-in attribute
+note: `repr` could also refer to the attribute macro imported here
   --> $DIR/ambiguous-builtin-attrs.rs:7:5
    |
 LL | use builtin_attrs::*;
    |     ^^^^^^^^^^^^^^^^
-note: `repr` could also refer to the name defined here
-  --> $DIR/ambiguous-builtin-attrs.rs:11:19
-   |
-LL | #[cfg_attr(all(), repr(C))] //~ ERROR `repr` is ambiguous
-   |                   ^^^^
-   = note: consider adding an explicit import of `repr` to disambiguate
+   = help: use `self::repr` to refer to this attribute macro unambiguously
 
-error[E0659]: `repr` is ambiguous
+error[E0659]: `repr` is ambiguous (built-in attribute vs any other name)
   --> $DIR/ambiguous-builtin-attrs.rs:20:34
    |
 LL | fn non_macro_expanded_location<#[repr(C)] T>() { //~ ERROR `repr` is ambiguous
    |                                  ^^^^ ambiguous name
    |
-note: `repr` could refer to the name imported here
+   = note: `repr` could refer to a built-in attribute
+note: `repr` could also refer to the attribute macro imported here
   --> $DIR/ambiguous-builtin-attrs.rs:7:5
    |
 LL | use builtin_attrs::*;
    |     ^^^^^^^^^^^^^^^^
-note: `repr` could also refer to the name defined here
-  --> $DIR/ambiguous-builtin-attrs.rs:20:34
-   |
-LL | fn non_macro_expanded_location<#[repr(C)] T>() { //~ ERROR `repr` is ambiguous
-   |                                  ^^^^
-   = note: consider adding an explicit import of `repr` to disambiguate
+   = help: use `self::repr` to refer to this attribute macro unambiguously
 
-error[E0659]: `repr` is ambiguous
+error[E0659]: `repr` is ambiguous (built-in attribute vs any other name)
   --> $DIR/ambiguous-builtin-attrs.rs:22:11
    |
 LL |         #[repr(C)] //~ ERROR `repr` is ambiguous
    |           ^^^^ ambiguous name
    |
-note: `repr` could refer to the name imported here
+   = note: `repr` could refer to a built-in attribute
+note: `repr` could also refer to the attribute macro imported here
   --> $DIR/ambiguous-builtin-attrs.rs:7:5
    |
 LL | use builtin_attrs::*;
    |     ^^^^^^^^^^^^^^^^
-note: `repr` could also refer to the name defined here
-  --> $DIR/ambiguous-builtin-attrs.rs:22:11
-   |
-LL |         #[repr(C)] //~ ERROR `repr` is ambiguous
-   |           ^^^^
-   = note: consider adding an explicit import of `repr` to disambiguate
+   = help: use `self::repr` to refer to this attribute macro unambiguously
 
-error[E0659]: `feature` is ambiguous
+error[E0659]: `feature` is ambiguous (built-in attribute vs any other name)
   --> $DIR/ambiguous-builtin-attrs.rs:3:4
    |
 LL | #![feature(decl_macro)] //~ ERROR `feature` is ambiguous
    |    ^^^^^^^ ambiguous name
    |
-note: `feature` could refer to the name imported here
+   = note: `feature` could refer to a built-in attribute
+note: `feature` could also refer to the attribute macro imported here
   --> $DIR/ambiguous-builtin-attrs.rs:7:5
    |
 LL | use builtin_attrs::*;
    |     ^^^^^^^^^^^^^^^^
-note: `feature` could also refer to the name defined here
-  --> $DIR/ambiguous-builtin-attrs.rs:3:4
-   |
-LL | #![feature(decl_macro)] //~ ERROR `feature` is ambiguous
-   |    ^^^^^^^
-   = note: consider adding an explicit import of `feature` to disambiguate
-
-error[E0425]: cannot find value `NonExistent` in this scope
-  --> $DIR/ambiguous-builtin-attrs.rs:30:5
-   |
-LL |     NonExistent; //~ ERROR cannot find value `NonExistent` in this scope
-   |     ^^^^^^^^^^^ not found in this scope
+   = help: use `self::feature` to refer to this attribute macro unambiguously
 
 error: aborting due to 6 previous errors
 
diff --git a/src/test/ui-fulldeps/proc-macro/derive-helper-shadowing.stderr b/src/test/ui-fulldeps/proc-macro/derive-helper-shadowing.stderr
index e0aeae4ba6c..f04782fac4d 100644
--- a/src/test/ui-fulldeps/proc-macro/derive-helper-shadowing.stderr
+++ b/src/test/ui-fulldeps/proc-macro/derive-helper-shadowing.stderr
@@ -1,19 +1,20 @@
-error[E0659]: `my_attr` is ambiguous
+error[E0659]: `my_attr` is ambiguous (derive helper attribute vs any other name)
   --> $DIR/derive-helper-shadowing.rs:6:3
    |
 LL | #[my_attr] //~ ERROR `my_attr` is ambiguous
    |   ^^^^^^^ ambiguous name
    |
-note: `my_attr` could refer to the name defined here
+note: `my_attr` could refer to the derive helper attribute defined here
   --> $DIR/derive-helper-shadowing.rs:7:10
    |
 LL | #[derive(MyTrait)]
    |          ^^^^^^^
-note: `my_attr` could also refer to the name imported here
+note: `my_attr` could also refer to the attribute macro imported here
   --> $DIR/derive-helper-shadowing.rs:4:5
    |
 LL | use derive_helper_shadowing::*;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = help: use `self::my_attr` to refer to this attribute macro unambiguously
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/absolute-paths-in-nested-use-groups.stderr b/src/test/ui/absolute-paths-in-nested-use-groups.stderr
index e88d26718a0..2bbd7b0ad3a 100644
--- a/src/test/ui/absolute-paths-in-nested-use-groups.stderr
+++ b/src/test/ui/absolute-paths-in-nested-use-groups.stderr
@@ -1,16 +1,16 @@
-error[E0433]: failed to resolve. crate root in paths can only be used in start position
+error[E0433]: failed to resolve: crate root in paths can only be used in start position
   --> $DIR/absolute-paths-in-nested-use-groups.rs:16:5
    |
 LL |     ::bar,       //~ ERROR crate root in paths can only be used in start position
    |     ^ crate root in paths can only be used in start position
 
-error[E0433]: failed to resolve. `super` in paths can only be used in start position
+error[E0433]: failed to resolve: `super` in paths can only be used in start position
   --> $DIR/absolute-paths-in-nested-use-groups.rs:17:5
    |
 LL |     super::bar,  //~ ERROR `super` in paths can only be used in start position
    |     ^^^^^ `super` in paths can only be used in start position
 
-error[E0433]: failed to resolve. `self` in paths can only be used in start position
+error[E0433]: failed to resolve: `self` in paths can only be used in start position
   --> $DIR/absolute-paths-in-nested-use-groups.rs:18:5
    |
 LL |     self::bar,   //~ ERROR `self` in paths can only be used in start position
diff --git a/src/test/ui/bad/bad-module.rs b/src/test/ui/bad/bad-module.rs
index 6987d06ef12..4f38d4ce45e 100644
--- a/src/test/ui/bad/bad-module.rs
+++ b/src/test/ui/bad/bad-module.rs
@@ -10,8 +10,8 @@
 
 fn main() {
     let foo = thing::len(Vec::new());
-    //~^ ERROR failed to resolve. Use of undeclared type or module `thing`
+    //~^ ERROR failed to resolve: use of undeclared type or module `thing`
 
     let foo = foo::bar::baz();
-    //~^ ERROR failed to resolve. Use of undeclared type or module `foo`
+    //~^ ERROR failed to resolve: use of undeclared type or module `foo`
 }
diff --git a/src/test/ui/bad/bad-module.stderr b/src/test/ui/bad/bad-module.stderr
index 8c19922dcab..8bdcceaa191 100644
--- a/src/test/ui/bad/bad-module.stderr
+++ b/src/test/ui/bad/bad-module.stderr
@@ -1,14 +1,14 @@
-error[E0433]: failed to resolve. Use of undeclared type or module `thing`
+error[E0433]: failed to resolve: use of undeclared type or module `thing`
   --> $DIR/bad-module.rs:12:15
    |
 LL |     let foo = thing::len(Vec::new());
-   |               ^^^^^ Use of undeclared type or module `thing`
+   |               ^^^^^ use of undeclared type or module `thing`
 
-error[E0433]: failed to resolve. Use of undeclared type or module `foo`
+error[E0433]: failed to resolve: use of undeclared type or module `foo`
   --> $DIR/bad-module.rs:15:15
    |
 LL |     let foo = foo::bar::baz();
-   |               ^^^ Use of undeclared type or module `foo`
+   |               ^^^ use of undeclared type or module `foo`
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/custom-attribute-multisegment.rs b/src/test/ui/custom-attribute-multisegment.rs
index a8d82a35946..354f7173872 100644
--- a/src/test/ui/custom-attribute-multisegment.rs
+++ b/src/test/ui/custom-attribute-multisegment.rs
@@ -14,5 +14,5 @@
 
 mod existent {}
 
-#[existent::nonexistent] //~ ERROR failed to resolve. Could not find `nonexistent` in `existent`
+#[existent::nonexistent] //~ ERROR failed to resolve: could not find `nonexistent` in `existent`
 fn main() {}
diff --git a/src/test/ui/custom-attribute-multisegment.stderr b/src/test/ui/custom-attribute-multisegment.stderr
index ff72d1c36d8..690ba4982ab 100644
--- a/src/test/ui/custom-attribute-multisegment.stderr
+++ b/src/test/ui/custom-attribute-multisegment.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve. Could not find `nonexistent` in `existent`
+error[E0433]: failed to resolve: could not find `nonexistent` in `existent`
   --> $DIR/custom-attribute-multisegment.rs:17:13
    |
-LL | #[existent::nonexistent] //~ ERROR failed to resolve. Could not find `nonexistent` in `existent`
-   |             ^^^^^^^^^^^ Could not find `nonexistent` in `existent`
+LL | #[existent::nonexistent] //~ ERROR failed to resolve: could not find `nonexistent` in `existent`
+   |             ^^^^^^^^^^^ could not find `nonexistent` in `existent`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/derived-errors/issue-31997-1.stderr b/src/test/ui/derived-errors/issue-31997-1.stderr
index 7cdcac3891f..5c5422f091b 100644
--- a/src/test/ui/derived-errors/issue-31997-1.stderr
+++ b/src/test/ui/derived-errors/issue-31997-1.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve. Use of undeclared type or module `HashMap`
+error[E0433]: failed to resolve: use of undeclared type or module `HashMap`
   --> $DIR/issue-31997-1.rs:30:19
    |
 LL |     let mut map = HashMap::new();
-   |                   ^^^^^^^ Use of undeclared type or module `HashMap`
+   |                   ^^^^^^^ use of undeclared type or module `HashMap`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/dollar-crate/dollar-crate-is-keyword-2.stderr b/src/test/ui/dollar-crate/dollar-crate-is-keyword-2.stderr
index 0a0b1d573dd..fe9af74c01d 100644
--- a/src/test/ui/dollar-crate/dollar-crate-is-keyword-2.stderr
+++ b/src/test/ui/dollar-crate/dollar-crate-is-keyword-2.stderr
@@ -1,4 +1,4 @@
-error[E0433]: failed to resolve. `$crate` in paths can only be used in start position
+error[E0433]: failed to resolve: `$crate` in paths can only be used in start position
   --> $DIR/dollar-crate-is-keyword-2.rs:16:16
    |
 LL |         use a::$crate::b; //~ ERROR `$crate` in paths can only be used in start position
@@ -16,7 +16,7 @@ LL |         use a::$crate; //~ ERROR unresolved import `a::$crate`
 LL | m!();
    | ----- in this macro invocation
 
-error[E0433]: failed to resolve. `$crate` in paths can only be used in start position
+error[E0433]: failed to resolve: `$crate` in paths can only be used in start position
   --> $DIR/dollar-crate-is-keyword-2.rs:17:21
    |
 LL |         type A = a::$crate; //~ ERROR `$crate` in paths can only be used in start position
diff --git a/src/test/ui/dyn-trait-compatibility.rs b/src/test/ui/dyn-trait-compatibility.rs
index 454b6d2f566..4297e1b43d3 100644
--- a/src/test/ui/dyn-trait-compatibility.rs
+++ b/src/test/ui/dyn-trait-compatibility.rs
@@ -11,7 +11,7 @@
 type A0 = dyn;
 //~^ ERROR cannot find type `dyn` in this scope
 type A1 = dyn::dyn;
-//~^ ERROR Use of undeclared type or module `dyn`
+//~^ ERROR use of undeclared type or module `dyn`
 type A2 = dyn<dyn, dyn>;
 //~^ ERROR cannot find type `dyn` in this scope
 //~| ERROR cannot find type `dyn` in this scope
@@ -19,6 +19,6 @@ type A2 = dyn<dyn, dyn>;
 type A3 = dyn<<dyn as dyn>::dyn>;
 //~^ ERROR cannot find type `dyn` in this scope
 //~| ERROR cannot find type `dyn` in this scope
-//~| ERROR Use of undeclared type or module `dyn`
+//~| ERROR use of undeclared type or module `dyn`
 
 fn main() {}
diff --git a/src/test/ui/dyn-trait-compatibility.stderr b/src/test/ui/dyn-trait-compatibility.stderr
index 1ff3249371b..93048ccad6f 100644
--- a/src/test/ui/dyn-trait-compatibility.stderr
+++ b/src/test/ui/dyn-trait-compatibility.stderr
@@ -1,14 +1,14 @@
-error[E0433]: failed to resolve. Use of undeclared type or module `dyn`
+error[E0433]: failed to resolve: use of undeclared type or module `dyn`
   --> $DIR/dyn-trait-compatibility.rs:13:11
    |
 LL | type A1 = dyn::dyn;
-   |           ^^^ Use of undeclared type or module `dyn`
+   |           ^^^ use of undeclared type or module `dyn`
 
-error[E0433]: failed to resolve. Use of undeclared type or module `dyn`
+error[E0433]: failed to resolve: use of undeclared type or module `dyn`
   --> $DIR/dyn-trait-compatibility.rs:19:23
    |
 LL | type A3 = dyn<<dyn as dyn>::dyn>;
-   |                       ^^^ Use of undeclared type or module `dyn`
+   |                       ^^^ use of undeclared type or module `dyn`
 
 error[E0412]: cannot find type `dyn` in this scope
   --> $DIR/dyn-trait-compatibility.rs:11:11
diff --git a/src/test/ui/empty/empty-struct-tuple-pat.stderr b/src/test/ui/empty/empty-struct-tuple-pat.stderr
index 3d219b1752f..3708aa36089 100644
--- a/src/test/ui/empty/empty-struct-tuple-pat.stderr
+++ b/src/test/ui/empty/empty-struct-tuple-pat.stderr
@@ -2,7 +2,7 @@ error[E0530]: match bindings cannot shadow tuple structs
   --> $DIR/empty-struct-tuple-pat.rs:32:9
    |
 LL | struct Empty2();
-   | ---------------- a tuple struct `Empty2` is defined here
+   | ---------------- the tuple struct `Empty2` is defined here
 ...
 LL |         Empty2 => () //~ ERROR match bindings cannot shadow tuple structs
    |         ^^^^^^ cannot be named the same as a tuple struct
@@ -11,7 +11,7 @@ error[E0530]: match bindings cannot shadow tuple structs
   --> $DIR/empty-struct-tuple-pat.rs:35:9
    |
 LL | use empty_struct::*;
-   |     --------------- a tuple struct `XEmpty6` is imported here
+   |     --------------- the tuple struct `XEmpty6` is imported here
 ...
 LL |         XEmpty6 => () //~ ERROR match bindings cannot shadow tuple structs
    |         ^^^^^^^ cannot be named the same as a tuple struct
diff --git a/src/test/ui/enum/enum-in-scope.stderr b/src/test/ui/enum/enum-in-scope.stderr
index 1e8d5940495..b294aabb4ed 100644
--- a/src/test/ui/enum/enum-in-scope.stderr
+++ b/src/test/ui/enum/enum-in-scope.stderr
@@ -2,7 +2,7 @@ error[E0530]: let bindings cannot shadow tuple structs
   --> $DIR/enum-in-scope.rs:14:9
    |
 LL | struct hello(isize);
-   | -------------------- a tuple struct `hello` is defined here
+   | -------------------- the tuple struct `hello` is defined here
 ...
 LL |     let hello = 0; //~ERROR let bindings cannot shadow tuple structs
    |         ^^^^^ cannot be named the same as a tuple struct
diff --git a/src/test/ui/error-codes/E0432.stderr b/src/test/ui/error-codes/E0432.stderr
index 291bb450755..d288cd086e7 100644
--- a/src/test/ui/error-codes/E0432.stderr
+++ b/src/test/ui/error-codes/E0432.stderr
@@ -2,7 +2,7 @@ error[E0432]: unresolved import `something`
   --> $DIR/E0432.rs:11:5
    |
 LL | use something::Foo; //~ ERROR E0432
-   |     ^^^^^^^^^ Maybe a missing `extern crate something;`?
+   |     ^^^^^^^^^ maybe a missing `extern crate something;`?
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/error-codes/E0433.stderr b/src/test/ui/error-codes/E0433.stderr
index f8cf5f6f92f..8a66e749ba8 100644
--- a/src/test/ui/error-codes/E0433.stderr
+++ b/src/test/ui/error-codes/E0433.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve. Use of undeclared type or module `HashMap`
+error[E0433]: failed to resolve: use of undeclared type or module `HashMap`
   --> $DIR/E0433.rs:12:15
    |
 LL |     let map = HashMap::new(); //~ ERROR E0433
-   |               ^^^^^^^ Use of undeclared type or module `HashMap`
+   |               ^^^^^^^ use of undeclared type or module `HashMap`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/error-codes/E0530.stderr b/src/test/ui/error-codes/E0530.stderr
index e157ca9042c..96bc47a1afe 100644
--- a/src/test/ui/error-codes/E0530.stderr
+++ b/src/test/ui/error-codes/E0530.stderr
@@ -2,7 +2,7 @@ error[E0530]: match bindings cannot shadow statics
   --> $DIR/E0530.rs:16:9
    |
 LL |     static TEST: i32 = 0;
-   |     --------------------- a static `TEST` is defined here
+   |     --------------------- the static `TEST` is defined here
 ...
 LL |         TEST => {} //~ ERROR E0530
    |         ^^^^ cannot be named the same as a static
diff --git a/src/test/ui/error-codes/E0659.stderr b/src/test/ui/error-codes/E0659.stderr
index f168b7797ca..7bfe159405b 100644
--- a/src/test/ui/error-codes/E0659.stderr
+++ b/src/test/ui/error-codes/E0659.stderr
@@ -1,20 +1,21 @@
-error[E0659]: `foo` is ambiguous
+error[E0659]: `foo` is ambiguous (glob import vs glob import in the same module)
   --> $DIR/E0659.rs:25:15
    |
 LL |     collider::foo(); //~ ERROR E0659
    |               ^^^ ambiguous name
    |
-note: `foo` could refer to the name imported here
+note: `foo` could refer to the function imported here
   --> $DIR/E0659.rs:20:13
    |
 LL |     pub use moon::*;
    |             ^^^^^^^
-note: `foo` could also refer to the name imported here
+   = help: consider adding an explicit import of `foo` to disambiguate
+note: `foo` could also refer to the function imported here
   --> $DIR/E0659.rs:21:13
    |
 LL |     pub use earth::*;
    |             ^^^^^^^^
-   = note: consider adding an explicit import of `foo` to disambiguate
+   = help: consider adding an explicit import of `foo` to disambiguate
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/export-fully-qualified.rs b/src/test/ui/export-fully-qualified.rs
index 19fa13f8377..422cd251de4 100644
--- a/src/test/ui/export-fully-qualified.rs
+++ b/src/test/ui/export-fully-qualified.rs
@@ -13,7 +13,7 @@
 // want to change eventually.
 
 mod foo {
-    pub fn bar() { foo::baz(); } //~ ERROR failed to resolve. Use of undeclared type or module `foo`
+    pub fn bar() { foo::baz(); } //~ ERROR failed to resolve: use of undeclared type or module `foo`
 
     fn baz() { }
 }
diff --git a/src/test/ui/export-fully-qualified.stderr b/src/test/ui/export-fully-qualified.stderr
index b8409929763..477cb4b1dd1 100644
--- a/src/test/ui/export-fully-qualified.stderr
+++ b/src/test/ui/export-fully-qualified.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve. Use of undeclared type or module `foo`
+error[E0433]: failed to resolve: use of undeclared type or module `foo`
   --> $DIR/export-fully-qualified.rs:16:20
    |
-LL |     pub fn bar() { foo::baz(); } //~ ERROR failed to resolve. Use of undeclared type or module `foo`
-   |                    ^^^ Use of undeclared type or module `foo`
+LL |     pub fn bar() { foo::baz(); } //~ ERROR failed to resolve: use of undeclared type or module `foo`
+   |                    ^^^ use of undeclared type or module `foo`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/export2.rs b/src/test/ui/export2.rs
index dc96ce7f504..4cc9762d975 100644
--- a/src/test/ui/export2.rs
+++ b/src/test/ui/export2.rs
@@ -9,7 +9,7 @@
 // except according to those terms.
 
 mod foo {
-    pub fn x() { bar::x(); } //~ ERROR failed to resolve. Use of undeclared type or module `bar`
+    pub fn x() { bar::x(); } //~ ERROR failed to resolve: use of undeclared type or module `bar`
 }
 
 mod bar {
diff --git a/src/test/ui/export2.stderr b/src/test/ui/export2.stderr
index c76afb8a1e2..7659183c8e0 100644
--- a/src/test/ui/export2.stderr
+++ b/src/test/ui/export2.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve. Use of undeclared type or module `bar`
+error[E0433]: failed to resolve: use of undeclared type or module `bar`
   --> $DIR/export2.rs:12:18
    |
-LL |     pub fn x() { bar::x(); } //~ ERROR failed to resolve. Use of undeclared type or module `bar`
-   |                  ^^^ Use of undeclared type or module `bar`
+LL |     pub fn x() { bar::x(); } //~ ERROR failed to resolve: use of undeclared type or module `bar`
+   |                  ^^^ use of undeclared type or module `bar`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/extern/extern-macro.rs b/src/test/ui/extern/extern-macro.rs
index 4b1bf7d8f79..88a72778a85 100644
--- a/src/test/ui/extern/extern-macro.rs
+++ b/src/test/ui/extern/extern-macro.rs
@@ -12,5 +12,5 @@
 
 fn main() {
     enum Foo {}
-    let _ = Foo::bar!(); //~ ERROR fail to resolve non-ident macro path
+    let _ = Foo::bar!(); //~ ERROR failed to resolve: partially resolved path in a macro
 }
diff --git a/src/test/ui/extern/extern-macro.stderr b/src/test/ui/extern/extern-macro.stderr
index b5515bfcc64..6123d970166 100644
--- a/src/test/ui/extern/extern-macro.stderr
+++ b/src/test/ui/extern/extern-macro.stderr
@@ -1,8 +1,9 @@
-error: fail to resolve non-ident macro path
+error[E0433]: failed to resolve: partially resolved path in a macro
   --> $DIR/extern-macro.rs:15:13
    |
-LL |     let _ = Foo::bar!(); //~ ERROR fail to resolve non-ident macro path
-   |             ^^^^^^^^
+LL |     let _ = Foo::bar!(); //~ ERROR failed to resolve: partially resolved path in a macro
+   |             ^^^^^^^^ partially resolved path in a macro
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0433`.
diff --git a/src/test/ui/feature-gates/feature-gate-extern_absolute_paths.stderr b/src/test/ui/feature-gates/feature-gate-extern_absolute_paths.stderr
index 7a996abc767..7c94200f00f 100644
--- a/src/test/ui/feature-gates/feature-gate-extern_absolute_paths.stderr
+++ b/src/test/ui/feature-gates/feature-gate-extern_absolute_paths.stderr
@@ -2,13 +2,13 @@ error[E0432]: unresolved import `core`
   --> $DIR/feature-gate-extern_absolute_paths.rs:11:5
    |
 LL | use core::default; //~ ERROR unresolved import `core`
-   |     ^^^^ Maybe a missing `extern crate core;`?
+   |     ^^^^ maybe a missing `extern crate core;`?
 
-error[E0433]: failed to resolve. Maybe a missing `extern crate core;`?
+error[E0433]: failed to resolve: maybe a missing `extern crate core;`?
   --> $DIR/feature-gate-extern_absolute_paths.rs:14:19
    |
 LL |     let _: u8 = ::core::default::Default(); //~ ERROR failed to resolve
-   |                   ^^^^ Maybe a missing `extern crate core;`?
+   |                   ^^^^ maybe a missing `extern crate core;`?
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/feature-gates/feature-gate-extern_crate_item_prelude.rs b/src/test/ui/feature-gates/feature-gate-extern_crate_item_prelude.rs
index a043b6c2e61..27b9a34ff4e 100644
--- a/src/test/ui/feature-gates/feature-gate-extern_crate_item_prelude.rs
+++ b/src/test/ui/feature-gates/feature-gate-extern_crate_item_prelude.rs
@@ -1,6 +1,6 @@
 // edition:2018
 
-#![feature(alloc)]
+#![feature(alloc, underscore_imports)]
 
 extern crate alloc;
 
@@ -23,7 +23,7 @@ mod absolute {
 }
 
 mod import_in_scope {
-    use alloc;
+    use alloc as _;
     //~^ ERROR use of extern prelude names introduced with `extern crate` items is unstable
     use alloc::boxed;
     //~^ ERROR use of extern prelude names introduced with `extern crate` items is unstable
diff --git a/src/test/ui/feature-gates/feature-gate-extern_crate_item_prelude.stderr b/src/test/ui/feature-gates/feature-gate-extern_crate_item_prelude.stderr
index bbd4b630263..103ab79ef84 100644
--- a/src/test/ui/feature-gates/feature-gate-extern_crate_item_prelude.stderr
+++ b/src/test/ui/feature-gates/feature-gate-extern_crate_item_prelude.stderr
@@ -1,7 +1,7 @@
 error[E0658]: use of extern prelude names introduced with `extern crate` items is unstable (see issue #55599)
   --> $DIR/feature-gate-extern_crate_item_prelude.rs:26:9
    |
-LL |     use alloc;
+LL |     use alloc as _;
    |         ^^^^^
    |
    = help: add #![feature(extern_crate_item_prelude)] to the crate attributes to enable
diff --git a/src/test/ui/feature-gates/feature-gate-uniform-paths.rs b/src/test/ui/feature-gates/feature-gate-uniform-paths.rs
index 140655d52bd..ca1cc1d2fd0 100644
--- a/src/test/ui/feature-gates/feature-gate-uniform-paths.rs
+++ b/src/test/ui/feature-gates/feature-gate-uniform-paths.rs
@@ -8,15 +8,22 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// edition:2018
+
 pub mod foo {
-    pub use bar::Bar;
-    //~^ ERROR unresolved import `bar`
+    pub use bar::Bar; //~ ERROR imports can only refer to extern crate names
 
     pub mod bar {
         pub struct Bar;
     }
 }
 
+use inline; //~ ERROR imports can only refer to extern crate names
+
+use Vec; //~ ERROR imports can only refer to extern crate names
+
+use vec; //~ ERROR imports can only refer to extern crate names
+
 fn main() {
     let _ = foo::Bar;
 }
diff --git a/src/test/ui/feature-gates/feature-gate-uniform-paths.stderr b/src/test/ui/feature-gates/feature-gate-uniform-paths.stderr
index 68faacfcbe7..ec8937bbc5f 100644
--- a/src/test/ui/feature-gates/feature-gate-uniform-paths.stderr
+++ b/src/test/ui/feature-gates/feature-gate-uniform-paths.stderr
@@ -1,9 +1,62 @@
-error[E0432]: unresolved import `bar`
-  --> $DIR/feature-gate-uniform-paths.rs:12:13
+error[E0658]: imports can only refer to extern crate names passed with `--extern` on stable channel (see issue #53130)
+  --> $DIR/feature-gate-uniform-paths.rs:14:13
    |
-LL |     pub use bar::Bar;
-   |             ^^^ Did you mean `self::bar`?
+LL |       pub use bar::Bar; //~ ERROR imports can only refer to extern crate names
+   |               ^^^
+LL | 
+LL | /     pub mod bar {
+LL | |         pub struct Bar;
+LL | |     }
+   | |_____- not an extern crate passed with `--extern`
+   |
+   = help: add #![feature(uniform_paths)] to the crate attributes to enable
+note: this import refers to the module defined here
+  --> $DIR/feature-gate-uniform-paths.rs:16:5
+   |
+LL | /     pub mod bar {
+LL | |         pub struct Bar;
+LL | |     }
+   | |_____^
+
+error[E0658]: imports can only refer to extern crate names passed with `--extern` on stable channel (see issue #53130)
+  --> $DIR/feature-gate-uniform-paths.rs:21:5
+   |
+LL | use inline; //~ ERROR imports can only refer to extern crate names
+   |     ^^^^^^ not an extern crate passed with `--extern`
+   |
+   = help: add #![feature(uniform_paths)] to the crate attributes to enable
+note: this import refers to the built-in attribute imported here
+  --> $DIR/feature-gate-uniform-paths.rs:21:5
+   |
+LL | use inline; //~ ERROR imports can only refer to extern crate names
+   |     ^^^^^^
+
+error[E0658]: imports can only refer to extern crate names passed with `--extern` on stable channel (see issue #53130)
+  --> $DIR/feature-gate-uniform-paths.rs:23:5
+   |
+LL | use Vec; //~ ERROR imports can only refer to extern crate names
+   |     ^^^ not an extern crate passed with `--extern`
+   |
+   = help: add #![feature(uniform_paths)] to the crate attributes to enable
+note: this import refers to the struct imported here
+  --> $DIR/feature-gate-uniform-paths.rs:23:5
+   |
+LL | use Vec; //~ ERROR imports can only refer to extern crate names
+   |     ^^^
+
+error[E0658]: imports can only refer to extern crate names passed with `--extern` on stable channel (see issue #53130)
+  --> $DIR/feature-gate-uniform-paths.rs:25:5
+   |
+LL | use vec; //~ ERROR imports can only refer to extern crate names
+   |     ^^^ not an extern crate passed with `--extern`
+   |
+   = help: add #![feature(uniform_paths)] to the crate attributes to enable
+note: this import refers to the macro imported here
+  --> $DIR/feature-gate-uniform-paths.rs:25:5
+   |
+LL | use vec; //~ ERROR imports can only refer to extern crate names
+   |     ^^^
 
-error: aborting due to previous error
+error: aborting due to 4 previous errors
 
-For more information about this error, try `rustc --explain E0432`.
+For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/hygiene/no_implicit_prelude.stderr b/src/test/ui/hygiene/no_implicit_prelude.stderr
index 463fdbf00ce..73a63a2c7f5 100644
--- a/src/test/ui/hygiene/no_implicit_prelude.stderr
+++ b/src/test/ui/hygiene/no_implicit_prelude.stderr
@@ -1,11 +1,11 @@
-error[E0433]: failed to resolve. Use of undeclared type or module `Vec`
+error[E0433]: failed to resolve: use of undeclared type or module `Vec`
   --> $DIR/no_implicit_prelude.rs:21:9
    |
 LL |     fn f() { ::bar::m!(); }
    |              ------------ in this macro invocation
 ...
 LL |         Vec::new(); //~ ERROR failed to resolve
-   |         ^^^ Use of undeclared type or module `Vec`
+   |         ^^^ use of undeclared type or module `Vec`
 
 error[E0599]: no method named `clone` found for type `()` in the current scope
   --> $DIR/no_implicit_prelude.rs:22:12
diff --git a/src/test/ui/import2.rs b/src/test/ui/import2.rs
index c4bd9ff1e2a..d3bbdf15cd0 100644
--- a/src/test/ui/import2.rs
+++ b/src/test/ui/import2.rs
@@ -9,7 +9,7 @@
 // except according to those terms.
 
 use baz::zed::bar; //~ ERROR unresolved import `baz::zed` [E0432]
-                   //~^ Could not find `zed` in `baz`
+                   //~^ could not find `zed` in `baz`
 
 mod baz {}
 mod zed {
diff --git a/src/test/ui/import2.stderr b/src/test/ui/import2.stderr
index c07506845c4..b1973937701 100644
--- a/src/test/ui/import2.stderr
+++ b/src/test/ui/import2.stderr
@@ -2,7 +2,7 @@ error[E0432]: unresolved import `baz::zed`
   --> $DIR/import2.rs:11:10
    |
 LL | use baz::zed::bar; //~ ERROR unresolved import `baz::zed` [E0432]
-   |          ^^^ Could not find `zed` in `baz`
+   |          ^^^ could not find `zed` in `baz`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/import3.stderr b/src/test/ui/import3.stderr
index 5211b862b3d..a4c367fb073 100644
--- a/src/test/ui/import3.stderr
+++ b/src/test/ui/import3.stderr
@@ -2,7 +2,7 @@ error[E0432]: unresolved import `main`
   --> $DIR/import3.rs:12:5
    |
 LL | use main::bar;
-   |     ^^^^ Maybe a missing `extern crate main;`?
+   |     ^^^^ maybe a missing `extern crate main;`?
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/imports/auxiliary/glob-conflict.rs b/src/test/ui/imports/auxiliary/glob-conflict.rs
new file mode 100644
index 00000000000..ac12ed9c81c
--- /dev/null
+++ b/src/test/ui/imports/auxiliary/glob-conflict.rs
@@ -0,0 +1,9 @@
+mod m1 {
+    pub fn f() {}
+}
+mod m2 {
+    pub fn f(_: u8) {}
+}
+
+pub use m1::*;
+pub use m2::*;
diff --git a/src/test/ui/imports/duplicate.stderr b/src/test/ui/imports/duplicate.stderr
index 5d51981e8af..f53ba9cd5de 100644
--- a/src/test/ui/imports/duplicate.stderr
+++ b/src/test/ui/imports/duplicate.stderr
@@ -12,77 +12,81 @@ help: you can use `as` to change the binding name of the import
 LL |     use a::foo as other_foo; //~ ERROR the name `foo` is defined multiple times
    |         ^^^^^^^^^^^^^^^^^^^
 
-error[E0659]: `foo` is ambiguous
+error[E0659]: `foo` is ambiguous (glob import vs glob import in the same module)
   --> $DIR/duplicate.rs:56:15
    |
 LL |     use self::foo::bar; //~ ERROR `foo` is ambiguous
    |               ^^^ ambiguous name
    |
-note: `foo` could refer to the name imported here
+note: `foo` could refer to the module imported here
   --> $DIR/duplicate.rs:53:9
    |
 LL |     use self::m1::*;
    |         ^^^^^^^^^^^
-note: `foo` could also refer to the name imported here
+   = help: consider adding an explicit import of `foo` to disambiguate
+note: `foo` could also refer to the module imported here
   --> $DIR/duplicate.rs:54:9
    |
 LL |     use self::m2::*;
    |         ^^^^^^^^^^^
-   = note: consider adding an explicit import of `foo` to disambiguate
+   = help: consider adding an explicit import of `foo` to disambiguate
 
-error[E0659]: `foo` is ambiguous
+error[E0659]: `foo` is ambiguous (glob import vs glob import in the same module)
   --> $DIR/duplicate.rs:45:8
    |
 LL |     f::foo(); //~ ERROR `foo` is ambiguous
    |        ^^^ ambiguous name
    |
-note: `foo` could refer to the name imported here
+note: `foo` could refer to the function imported here
   --> $DIR/duplicate.rs:34:13
    |
 LL |     pub use a::*;
    |             ^^^^
-note: `foo` could also refer to the name imported here
+   = help: consider adding an explicit import of `foo` to disambiguate
+note: `foo` could also refer to the function imported here
   --> $DIR/duplicate.rs:35:13
    |
 LL |     pub use b::*;
    |             ^^^^
-   = note: consider adding an explicit import of `foo` to disambiguate
+   = help: consider adding an explicit import of `foo` to disambiguate
 
-error[E0659]: `foo` is ambiguous
+error[E0659]: `foo` is ambiguous (glob import vs glob import in the same module)
   --> $DIR/duplicate.rs:46:8
    |
 LL |     g::foo(); //~ ERROR `foo` is ambiguous
    |        ^^^ ambiguous name
    |
-note: `foo` could refer to the name imported here
+note: `foo` could refer to the function imported here
   --> $DIR/duplicate.rs:39:13
    |
 LL |     pub use a::*;
    |             ^^^^
-note: `foo` could also refer to the name imported here
+   = help: consider adding an explicit import of `foo` to disambiguate
+note: `foo` could also refer to the unresolved item imported here
   --> $DIR/duplicate.rs:40:13
    |
 LL |     pub use f::*;
    |             ^^^^
-   = note: consider adding an explicit import of `foo` to disambiguate
+   = help: consider adding an explicit import of `foo` to disambiguate
 
-error[E0659]: `foo` is ambiguous
+error[E0659]: `foo` is ambiguous (glob import vs glob import in the same module)
   --> $DIR/duplicate.rs:59:9
    |
 LL |         foo::bar(); //~ ERROR `foo` is ambiguous
    |         ^^^ ambiguous name
    |
-note: `foo` could refer to the name imported here
+note: `foo` could refer to the module imported here
   --> $DIR/duplicate.rs:53:9
    |
 LL |     use self::m1::*;
    |         ^^^^^^^^^^^
-note: `foo` could also refer to the name imported here
+   = help: consider adding an explicit import of `foo` to disambiguate
+note: `foo` could also refer to the module imported here
   --> $DIR/duplicate.rs:54:9
    |
 LL |     use self::m2::*;
    |         ^^^^^^^^^^^
-   = note: consider adding an explicit import of `foo` to disambiguate
+   = help: consider adding an explicit import of `foo` to disambiguate
 
 error: aborting due to 5 previous errors
 
diff --git a/src/test/ui/imports/extern-prelude-extern-crate-fail.rs b/src/test/ui/imports/extern-prelude-extern-crate-fail.rs
index 57b097c9df3..6b70efe0c44 100644
--- a/src/test/ui/imports/extern-prelude-extern-crate-fail.rs
+++ b/src/test/ui/imports/extern-prelude-extern-crate-fail.rs
@@ -7,7 +7,7 @@ mod n {
 
 mod m {
     fn check() {
-        two_macros::m!(); //~ ERROR failed to resolve. Use of undeclared type or module `two_macros`
+        two_macros::m!(); //~ ERROR failed to resolve: use of undeclared type or module `two_macros`
     }
 }
 
diff --git a/src/test/ui/imports/extern-prelude-extern-crate-fail.stderr b/src/test/ui/imports/extern-prelude-extern-crate-fail.stderr
index 8f68d2af34c..baeed02517d 100644
--- a/src/test/ui/imports/extern-prelude-extern-crate-fail.stderr
+++ b/src/test/ui/imports/extern-prelude-extern-crate-fail.stderr
@@ -7,11 +7,11 @@ LL |         extern crate std as non_existent;
 LL | define_std_as_non_existent!();
    | ------------------------------ in this macro invocation
 
-error[E0433]: failed to resolve. Use of undeclared type or module `two_macros`
+error[E0433]: failed to resolve: use of undeclared type or module `two_macros`
   --> $DIR/extern-prelude-extern-crate-fail.rs:10:9
    |
-LL |         two_macros::m!(); //~ ERROR failed to resolve. Use of undeclared type or module `two_macros`
-   |         ^^^^^^^^^^ Use of undeclared type or module `two_macros`
+LL |         two_macros::m!(); //~ ERROR failed to resolve: use of undeclared type or module `two_macros`
+   |         ^^^^^^^^^^ use of undeclared type or module `two_macros`
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/imports/extern-prelude-extern-crate-restricted-shadowing.stderr b/src/test/ui/imports/extern-prelude-extern-crate-restricted-shadowing.stderr
index 6c832e70e49..218dfb796f7 100644
--- a/src/test/ui/imports/extern-prelude-extern-crate-restricted-shadowing.stderr
+++ b/src/test/ui/imports/extern-prelude-extern-crate-restricted-shadowing.stderr
@@ -1,10 +1,11 @@
-error[E0659]: `Vec` is ambiguous
+error[E0659]: `Vec` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/extern-prelude-extern-crate-restricted-shadowing.rs:15:9
    |
 LL |         Vec::panic!(); //~ ERROR `Vec` is ambiguous
    |         ^^^ ambiguous name
    |
-note: `Vec` could refer to the name defined here
+   = note: `Vec` could refer to a struct from prelude
+note: `Vec` could also refer to the extern crate imported here
   --> $DIR/extern-prelude-extern-crate-restricted-shadowing.rs:7:9
    |
 LL |         extern crate std as Vec;
@@ -12,8 +13,6 @@ LL |         extern crate std as Vec;
 ...
 LL | define_vec!();
    | -------------- in this macro invocation
-note: `Vec` could also refer to the name defined here
-   = note: macro-expanded items do not shadow when used in a macro invocation path
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/imports/glob-conflict-cross-crate.rs b/src/test/ui/imports/glob-conflict-cross-crate.rs
new file mode 100644
index 00000000000..e02148b19f7
--- /dev/null
+++ b/src/test/ui/imports/glob-conflict-cross-crate.rs
@@ -0,0 +1,7 @@
+// aux-build:glob-conflict.rs
+
+extern crate glob_conflict;
+
+fn main() {
+    glob_conflict::f(); //~ ERROR cannot find function `f` in module `glob_conflict`
+}
diff --git a/src/test/ui/imports/glob-conflict-cross-crate.stderr b/src/test/ui/imports/glob-conflict-cross-crate.stderr
new file mode 100644
index 00000000000..f64637fd6f6
--- /dev/null
+++ b/src/test/ui/imports/glob-conflict-cross-crate.stderr
@@ -0,0 +1,9 @@
+error[E0425]: cannot find function `f` in module `glob_conflict`
+  --> $DIR/glob-conflict-cross-crate.rs:6:20
+   |
+LL |     glob_conflict::f(); //~ ERROR cannot find function `f` in module `glob_conflict`
+   |                    ^ not found in `glob_conflict`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0425`.
diff --git a/src/test/ui/imports/glob-shadowing.stderr b/src/test/ui/imports/glob-shadowing.stderr
index 33a2963fa29..6a4774facd7 100644
--- a/src/test/ui/imports/glob-shadowing.stderr
+++ b/src/test/ui/imports/glob-shadowing.stderr
@@ -1,48 +1,50 @@
-error[E0659]: `env` is ambiguous
+error[E0659]: `env` is ambiguous (glob import vs any other name from outer scope during import/macro resolution)
   --> $DIR/glob-shadowing.rs:21:17
    |
 LL |         let x = env!("PATH"); //~ ERROR `env` is ambiguous
    |                 ^^^ ambiguous name
    |
-note: `env` could refer to the name imported here
+   = note: `env` could refer to a built-in macro
+note: `env` could also refer to the macro imported here
   --> $DIR/glob-shadowing.rs:19:9
    |
 LL |     use m::*;
    |         ^^^^
-   = note: `env` is also a builtin macro
-   = note: consider adding an explicit import of `env` to disambiguate
+   = help: consider adding an explicit import of `env` to disambiguate
+   = help: or use `self::env` to refer to this macro unambiguously
 
-error[E0659]: `env` is ambiguous
+error[E0659]: `env` is ambiguous (glob import vs any other name from outer scope during import/macro resolution)
   --> $DIR/glob-shadowing.rs:29:21
    |
 LL |             let x = env!("PATH"); //~ ERROR `env` is ambiguous
    |                     ^^^ ambiguous name
    |
-note: `env` could refer to the name imported here
+   = note: `env` could refer to a built-in macro
+note: `env` could also refer to the macro imported here
   --> $DIR/glob-shadowing.rs:27:13
    |
 LL |         use m::*;
    |             ^^^^
-   = note: `env` is also a builtin macro
-   = note: consider adding an explicit import of `env` to disambiguate
+   = help: consider adding an explicit import of `env` to disambiguate
 
-error[E0659]: `fenv` is ambiguous
+error[E0659]: `fenv` is ambiguous (glob import vs any other name from outer scope during import/macro resolution)
   --> $DIR/glob-shadowing.rs:39:21
    |
 LL |             let x = fenv!(); //~ ERROR `fenv` is ambiguous
    |                     ^^^^ ambiguous name
    |
-note: `fenv` could refer to the name imported here
+note: `fenv` could refer to the macro imported here
   --> $DIR/glob-shadowing.rs:37:13
    |
 LL |         use m::*;
    |             ^^^^
-note: `fenv` could also refer to the name defined here
+   = help: consider adding an explicit import of `fenv` to disambiguate
+note: `fenv` could also refer to the macro defined here
   --> $DIR/glob-shadowing.rs:35:5
    |
 LL |     pub macro fenv($e: expr) { $e }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   = note: consider adding an explicit import of `fenv` to disambiguate
+   = help: use `self::fenv` to refer to this macro unambiguously
 
 error: aborting due to 3 previous errors
 
diff --git a/src/test/ui/imports/issue-53269.stderr b/src/test/ui/imports/issue-53269.stderr
index e125983151d..0ed26ea6fe6 100644
--- a/src/test/ui/imports/issue-53269.stderr
+++ b/src/test/ui/imports/issue-53269.stderr
@@ -2,24 +2,25 @@ error[E0432]: unresolved import `nonexistent_module`
   --> $DIR/issue-53269.rs:16:9
    |
 LL |     use nonexistent_module::mac; //~ ERROR unresolved import `nonexistent_module`
-   |         ^^^^^^^^^^^^^^^^^^ Maybe a missing `extern crate nonexistent_module;`?
+   |         ^^^^^^^^^^^^^^^^^^ maybe a missing `extern crate nonexistent_module;`?
 
-error[E0659]: `mac` is ambiguous
+error[E0659]: `mac` is ambiguous (`macro_rules` vs non-`macro_rules` from other module)
   --> $DIR/issue-53269.rs:18:5
    |
 LL |     mac!(); //~ ERROR `mac` is ambiguous
    |     ^^^ ambiguous name
    |
-note: `mac` could refer to the name defined here
+note: `mac` could refer to the macro defined here
   --> $DIR/issue-53269.rs:13:1
    |
 LL | macro_rules! mac { () => () }
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-note: `mac` could also refer to the name imported here
+note: `mac` could also refer to the unresolved item imported here
   --> $DIR/issue-53269.rs:16:9
    |
 LL |     use nonexistent_module::mac; //~ ERROR unresolved import `nonexistent_module`
    |         ^^^^^^^^^^^^^^^^^^^^^^^
+   = help: use `self::mac` to refer to this unresolved item unambiguously
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/imports/issue-55457.stderr b/src/test/ui/imports/issue-55457.stderr
index 363dec06237..4ee0332d04b 100644
--- a/src/test/ui/imports/issue-55457.stderr
+++ b/src/test/ui/imports/issue-55457.stderr
@@ -8,7 +8,7 @@ error[E0432]: unresolved import `non_existent`
   --> $DIR/issue-55457.rs:2:5
    |
 LL | use non_existent::non_existent; //~ ERROR unresolved import `non_existent`
-   |     ^^^^^^^^^^^^ Maybe a missing `extern crate non_existent;`?
+   |     ^^^^^^^^^^^^ maybe a missing `extern crate non_existent;`?
 
 error: cannot determine resolution for the derive macro `NonExistent`
   --> $DIR/issue-55457.rs:5:10
diff --git a/src/test/ui/imports/issue-55884-1.rs b/src/test/ui/imports/issue-55884-1.rs
new file mode 100644
index 00000000000..21744aa5d7b
--- /dev/null
+++ b/src/test/ui/imports/issue-55884-1.rs
@@ -0,0 +1,21 @@
+mod m {
+    mod m1 {
+        pub struct S {}
+    }
+    mod m2 {
+        // Note this derive, it makes this struct macro-expanded,
+        // so it doesn't appear in time to participate in the initial resolution of `use m::S`,
+        // only in the later validation pass.
+        #[derive(Default)]
+        pub struct S {}
+    }
+
+    // Create a glob vs glob ambiguity
+    pub use self::m1::*;
+    pub use self::m2::*;
+}
+
+fn main() {
+    use m::S; //~ ERROR `S` is ambiguous
+    let s = S {};
+}
diff --git a/src/test/ui/imports/issue-55884-1.stderr b/src/test/ui/imports/issue-55884-1.stderr
new file mode 100644
index 00000000000..477e859d081
--- /dev/null
+++ b/src/test/ui/imports/issue-55884-1.stderr
@@ -0,0 +1,22 @@
+error[E0659]: `S` is ambiguous (glob import vs glob import in the same module)
+  --> $DIR/issue-55884-1.rs:19:12
+   |
+LL |     use m::S; //~ ERROR `S` is ambiguous
+   |            ^ ambiguous name
+   |
+note: `S` could refer to the struct imported here
+  --> $DIR/issue-55884-1.rs:14:13
+   |
+LL |     pub use self::m1::*;
+   |             ^^^^^^^^^^^
+   = help: consider adding an explicit import of `S` to disambiguate
+note: `S` could also refer to the struct imported here
+  --> $DIR/issue-55884-1.rs:15:13
+   |
+LL |     pub use self::m2::*;
+   |             ^^^^^^^^^^^
+   = help: consider adding an explicit import of `S` to disambiguate
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0659`.
diff --git a/src/test/ui/imports/issue-55884-2.rs b/src/test/ui/imports/issue-55884-2.rs
new file mode 100644
index 00000000000..1b4f652c9fc
--- /dev/null
+++ b/src/test/ui/imports/issue-55884-2.rs
@@ -0,0 +1,14 @@
+mod options {
+    pub struct ParseOptions {}
+}
+
+mod parser {
+    pub use options::*;
+    // Private single import shadows public glob import, but arrives too late for initial
+    // resolution of `use parser::ParseOptions` because it depends on that resolution itself.
+    use ParseOptions;
+}
+
+pub use parser::ParseOptions; //~ ERROR struct `ParseOptions` is private
+
+fn main() {}
diff --git a/src/test/ui/imports/issue-55884-2.stderr b/src/test/ui/imports/issue-55884-2.stderr
new file mode 100644
index 00000000000..f8a6cb4a580
--- /dev/null
+++ b/src/test/ui/imports/issue-55884-2.stderr
@@ -0,0 +1,9 @@
+error[E0603]: struct `ParseOptions` is private
+  --> $DIR/issue-55884-2.rs:12:17
+   |
+LL | pub use parser::ParseOptions; //~ ERROR struct `ParseOptions` is private
+   |                 ^^^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0603`.
diff --git a/src/test/ui/imports/local-modularized-tricky-fail-1.stderr b/src/test/ui/imports/local-modularized-tricky-fail-1.stderr
index 9c475451ce3..962294e48ca 100644
--- a/src/test/ui/imports/local-modularized-tricky-fail-1.stderr
+++ b/src/test/ui/imports/local-modularized-tricky-fail-1.stderr
@@ -1,10 +1,10 @@
-error[E0659]: `exported` is ambiguous
+error[E0659]: `exported` is ambiguous (glob import vs macro-expanded name in the same module during import/macro resolution)
   --> $DIR/local-modularized-tricky-fail-1.rs:38:1
    |
 LL | exported!(); //~ ERROR `exported` is ambiguous
    | ^^^^^^^^ ambiguous name
    |
-note: `exported` could refer to the name defined here
+note: `exported` could refer to the macro defined here
   --> $DIR/local-modularized-tricky-fail-1.rs:15:5
    |
 LL | /     macro_rules! exported {
@@ -14,20 +14,21 @@ LL | |     }
 ...
 LL |       define_exported!();
    |       ------------------- in this macro invocation
-note: `exported` could also refer to the name imported here
+note: `exported` could also refer to the macro imported here
   --> $DIR/local-modularized-tricky-fail-1.rs:32:5
    |
 LL | use inner1::*;
    |     ^^^^^^^^^
-   = note: macro-expanded macros do not shadow
+   = help: consider adding an explicit import of `exported` to disambiguate
 
-error[E0659]: `include` is ambiguous
+error[E0659]: `include` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/local-modularized-tricky-fail-1.rs:56:1
    |
 LL | include!(); //~ ERROR `include` is ambiguous
    | ^^^^^^^ ambiguous name
    |
-note: `include` could refer to the name defined here
+   = note: `include` could refer to a built-in macro
+note: `include` could also refer to the macro defined here
   --> $DIR/local-modularized-tricky-fail-1.rs:27:5
    |
 LL | /     macro_rules! include {
@@ -37,16 +38,16 @@ LL | |     }
 ...
 LL |       define_include!();
    |       ------------------ in this macro invocation
-   = note: `include` is also a builtin macro
-   = note: macro-expanded macros do not shadow
+   = help: use `self::include` to refer to this macro unambiguously
 
-error[E0659]: `panic` is ambiguous
+error[E0659]: `panic` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/local-modularized-tricky-fail-1.rs:45:5
    |
 LL |     panic!(); //~ ERROR `panic` is ambiguous
    |     ^^^^^ ambiguous name
    |
-note: `panic` could refer to the name defined here
+   = note: `panic` could refer to a macro from prelude
+note: `panic` could also refer to the macro defined here
   --> $DIR/local-modularized-tricky-fail-1.rs:21:5
    |
 LL | /     macro_rules! panic {
@@ -56,16 +57,16 @@ LL | |     }
 ...
 LL |       define_panic!();
    |       ---------------- in this macro invocation
-   = note: `panic` is also a builtin macro
-   = note: macro-expanded macros do not shadow
+   = help: use `self::panic` to refer to this macro unambiguously
 
-error[E0659]: `panic` is ambiguous
+error[E0659]: `panic` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> <::std::macros::panic macros>:1:13
    |
 LL | (  ) => ( { panic ! ( "explicit panic" ) } ) ; ( $ msg : expr ) => (
    |             ^^^^^ ambiguous name
    |
-note: `panic` could refer to the name defined here
+   = note: `panic` could refer to a macro from prelude
+note: `panic` could also refer to the macro defined here
   --> $DIR/local-modularized-tricky-fail-1.rs:21:5
    |
 LL | /     macro_rules! panic {
@@ -75,8 +76,7 @@ LL | |     }
 ...
 LL |       define_panic!();
    |       ---------------- in this macro invocation
-   = note: `panic` is also a builtin macro
-   = note: macro-expanded macros do not shadow
+   = help: use `self::panic` to refer to this macro unambiguously
 
 error: aborting due to 4 previous errors
 
diff --git a/src/test/ui/imports/macro-paths.stderr b/src/test/ui/imports/macro-paths.stderr
index a612c64c2f4..8e8742f849b 100644
--- a/src/test/ui/imports/macro-paths.stderr
+++ b/src/test/ui/imports/macro-paths.stderr
@@ -1,40 +1,40 @@
-error[E0659]: `bar` is ambiguous
+error[E0659]: `bar` is ambiguous (glob import vs macro-expanded name in the same module during import/macro resolution)
   --> $DIR/macro-paths.rs:23:5
    |
 LL |     bar::m! { //~ ERROR ambiguous
    |     ^^^ ambiguous name
    |
-note: `bar` could refer to the name defined here
+note: `bar` could refer to the module defined here
   --> $DIR/macro-paths.rs:24:9
    |
 LL |         mod bar { pub use two_macros::m; }
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-note: `bar` could also refer to the name imported here
+note: `bar` could also refer to the module imported here
   --> $DIR/macro-paths.rs:22:9
    |
 LL |     use foo::*;
    |         ^^^^^^
-   = note: macro-expanded items do not shadow when used in a macro invocation path
+   = help: consider adding an explicit import of `bar` to disambiguate
 
-error[E0659]: `baz` is ambiguous
+error[E0659]: `baz` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/macro-paths.rs:33:5
    |
 LL |     baz::m! { //~ ERROR ambiguous
    |     ^^^ ambiguous name
    |
-note: `baz` could refer to the name defined here
+note: `baz` could refer to the module defined here
   --> $DIR/macro-paths.rs:34:9
    |
 LL |         mod baz { pub use two_macros::m; }
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-note: `baz` could also refer to the name defined here
+note: `baz` could also refer to the module defined here
   --> $DIR/macro-paths.rs:28:1
    |
 LL | / pub mod baz {
 LL | |     pub use two_macros::m;
 LL | | }
    | |_^
-   = note: macro-expanded items do not shadow when used in a macro invocation path
+   = help: use `self::baz` to refer to this module unambiguously
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/imports/macros.stderr b/src/test/ui/imports/macros.stderr
index 209d449dfd8..77a0311fa60 100644
--- a/src/test/ui/imports/macros.stderr
+++ b/src/test/ui/imports/macros.stderr
@@ -1,38 +1,38 @@
-error[E0659]: `m` is ambiguous
+error[E0659]: `m` is ambiguous (glob import vs macro-expanded name in the same module during import/macro resolution)
   --> $DIR/macros.rs:26:5
    |
 LL |     m! { //~ ERROR ambiguous
    |     ^ ambiguous name
    |
-note: `m` could refer to the name imported here
+note: `m` could refer to the macro imported here
   --> $DIR/macros.rs:27:13
    |
 LL |         use foo::m;
    |             ^^^^^^
-note: `m` could also refer to the name imported here
+note: `m` could also refer to the macro imported here
   --> $DIR/macros.rs:25:9
    |
 LL |     use two_macros::*;
    |         ^^^^^^^^^^^^^
-   = note: macro-expanded macro imports do not shadow
+   = help: consider adding an explicit import of `m` to disambiguate
 
-error[E0659]: `m` is ambiguous
+error[E0659]: `m` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/macros.rs:39:9
    |
 LL |         m! { //~ ERROR ambiguous
    |         ^ ambiguous name
    |
-note: `m` could refer to the name imported here
+note: `m` could refer to the macro imported here
   --> $DIR/macros.rs:40:17
    |
 LL |             use two_macros::n as m;
    |                 ^^^^^^^^^^^^^^^^^^
-note: `m` could also refer to the name imported here
+note: `m` could also refer to the macro imported here
   --> $DIR/macros.rs:32:9
    |
 LL |     use two_macros::m;
    |         ^^^^^^^^^^^^^
-   = note: macro-expanded macro imports do not shadow
+   = help: use `self::m` to refer to this macro unambiguously
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/imports/rfc-1560-warning-cycle.stderr b/src/test/ui/imports/rfc-1560-warning-cycle.stderr
index 91af3a4b6ac..946dc084cd0 100644
--- a/src/test/ui/imports/rfc-1560-warning-cycle.stderr
+++ b/src/test/ui/imports/rfc-1560-warning-cycle.stderr
@@ -1,20 +1,21 @@
-error[E0659]: `Foo` is ambiguous
+error[E0659]: `Foo` is ambiguous (glob import vs glob import in the same module)
   --> $DIR/rfc-1560-warning-cycle.rs:19:17
    |
 LL |         fn f(_: Foo) {} //~ ERROR `Foo` is ambiguous
    |                 ^^^ ambiguous name
    |
-note: `Foo` could refer to the name imported here
+note: `Foo` could refer to the struct imported here
   --> $DIR/rfc-1560-warning-cycle.rs:17:13
    |
 LL |         use *;
    |             ^
-note: `Foo` could also refer to the name imported here
+   = help: consider adding an explicit import of `Foo` to disambiguate
+note: `Foo` could also refer to the struct imported here
   --> $DIR/rfc-1560-warning-cycle.rs:18:13
    |
 LL |         use bar::*;
    |             ^^^^^^
-   = note: consider adding an explicit import of `Foo` to disambiguate
+   = help: consider adding an explicit import of `Foo` to disambiguate
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/imports/shadow_builtin_macros.stderr b/src/test/ui/imports/shadow_builtin_macros.stderr
index 7e5ab0c5abe..b53b7e2700d 100644
--- a/src/test/ui/imports/shadow_builtin_macros.stderr
+++ b/src/test/ui/imports/shadow_builtin_macros.stderr
@@ -1,38 +1,40 @@
-error[E0659]: `panic` is ambiguous
+error[E0659]: `panic` is ambiguous (glob import vs any other name from outer scope during import/macro resolution)
   --> $DIR/shadow_builtin_macros.rs:25:14
    |
 LL |     fn f() { panic!(); } //~ ERROR ambiguous
    |              ^^^^^ ambiguous name
    |
-note: `panic` could refer to the name imported here
+   = note: `panic` could refer to a macro from prelude
+note: `panic` could also refer to the macro imported here
   --> $DIR/shadow_builtin_macros.rs:24:9
    |
 LL |     use foo::*;
    |         ^^^^^^
-   = note: `panic` is also a builtin macro
-   = note: consider adding an explicit import of `panic` to disambiguate
+   = help: consider adding an explicit import of `panic` to disambiguate
+   = help: or use `self::panic` to refer to this macro unambiguously
 
-error[E0659]: `panic` is ambiguous
+error[E0659]: `panic` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/shadow_builtin_macros.rs:30:14
    |
 LL |     fn f() { panic!(); } //~ ERROR ambiguous
    |              ^^^^^ ambiguous name
    |
-note: `panic` could refer to the name imported here
+   = note: `panic` could refer to a macro from prelude
+note: `panic` could also refer to the macro imported here
   --> $DIR/shadow_builtin_macros.rs:29:26
    |
 LL |     ::two_macros::m!(use foo::panic;);
    |                          ^^^^^^^^^^
-   = note: `panic` is also a builtin macro
-   = note: macro-expanded macro imports do not shadow
+   = help: use `self::panic` to refer to this macro unambiguously
 
-error[E0659]: `panic` is ambiguous
+error[E0659]: `panic` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/shadow_builtin_macros.rs:43:5
    |
 LL |     panic!(); //~ ERROR `panic` is ambiguous
    |     ^^^^^ ambiguous name
    |
-note: `panic` could refer to the name defined here
+   = note: `panic` could refer to a macro from prelude
+note: `panic` could also refer to the macro defined here
   --> $DIR/shadow_builtin_macros.rs:40:9
    |
 LL |         macro_rules! panic { () => {} }
@@ -40,26 +42,25 @@ LL |         macro_rules! panic { () => {} }
 LL |     } }
 LL |     m!();
    |     ----- in this macro invocation
-   = note: `panic` is also a builtin macro
-   = note: macro-expanded macros do not shadow
 
-error[E0659]: `n` is ambiguous
+error[E0659]: `n` is ambiguous (glob import vs any other name from outer scope during import/macro resolution)
   --> $DIR/shadow_builtin_macros.rs:59:5
    |
 LL |     n!(); //~ ERROR ambiguous
    |     ^ ambiguous name
    |
-note: `n` could refer to the name imported here
+note: `n` could refer to the macro imported here
   --> $DIR/shadow_builtin_macros.rs:58:9
    |
 LL |     use bar::*;
    |         ^^^^^^
-note: `n` could also refer to the name imported here
+   = help: consider adding an explicit import of `n` to disambiguate
+   = help: or use `self::n` to refer to this macro unambiguously
+note: `n` could also refer to the macro imported here
   --> $DIR/shadow_builtin_macros.rs:46:13
    |
 LL | #[macro_use(n)]
    |             ^
-   = note: consider adding an explicit import of `n` to disambiguate
 
 error: aborting due to 4 previous errors
 
diff --git a/src/test/ui/issues/issue-16149.stderr b/src/test/ui/issues/issue-16149.stderr
index b0b6e9dfcd0..284ed035526 100644
--- a/src/test/ui/issues/issue-16149.stderr
+++ b/src/test/ui/issues/issue-16149.stderr
@@ -2,7 +2,7 @@ error[E0530]: match bindings cannot shadow statics
   --> $DIR/issue-16149.rs:17:9
    |
 LL |     static externalValue: isize;
-   |     ---------------------------- a static `externalValue` is defined here
+   |     ---------------------------- the static `externalValue` is defined here
 ...
 LL |         externalValue => true,
    |         ^^^^^^^^^^^^^ cannot be named the same as a static
diff --git a/src/test/ui/issues/issue-1697.rs b/src/test/ui/issues/issue-1697.rs
index f8a68264339..43f92d8c3de 100644
--- a/src/test/ui/issues/issue-1697.rs
+++ b/src/test/ui/issues/issue-1697.rs
@@ -11,6 +11,6 @@
 // Testing that we don't fail abnormally after hitting the errors
 
 use unresolved::*; //~ ERROR unresolved import `unresolved` [E0432]
-                   //~^ Maybe a missing `extern crate unresolved;`?
+                   //~^ maybe a missing `extern crate unresolved;`?
 
 fn main() {}
diff --git a/src/test/ui/issues/issue-1697.stderr b/src/test/ui/issues/issue-1697.stderr
index 28a7fbcaabe..b588c883264 100644
--- a/src/test/ui/issues/issue-1697.stderr
+++ b/src/test/ui/issues/issue-1697.stderr
@@ -2,7 +2,7 @@ error[E0432]: unresolved import `unresolved`
   --> $DIR/issue-1697.rs:13:5
    |
 LL | use unresolved::*; //~ ERROR unresolved import `unresolved` [E0432]
-   |     ^^^^^^^^^^ Maybe a missing `extern crate unresolved;`?
+   |     ^^^^^^^^^^ maybe a missing `extern crate unresolved;`?
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-17718-patterns.stderr b/src/test/ui/issues/issue-17718-patterns.stderr
index 13cab9a08b1..c49613eb33c 100644
--- a/src/test/ui/issues/issue-17718-patterns.stderr
+++ b/src/test/ui/issues/issue-17718-patterns.stderr
@@ -2,7 +2,7 @@ error[E0530]: match bindings cannot shadow statics
   --> $DIR/issue-17718-patterns.rs:17:9
    |
 LL | static A1: usize = 1;
-   | --------------------- a static `A1` is defined here
+   | --------------------- the static `A1` is defined here
 ...
 LL |         A1 => {} //~ ERROR: match bindings cannot shadow statics
    |         ^^ cannot be named the same as a static
@@ -11,7 +11,7 @@ error[E0530]: match bindings cannot shadow statics
   --> $DIR/issue-17718-patterns.rs:18:9
    |
 LL | static mut A2: usize = 1;
-   | ------------------------- a static `A2` is defined here
+   | ------------------------- the static `A2` is defined here
 ...
 LL |         A2 => {} //~ ERROR: match bindings cannot shadow statics
    |         ^^ cannot be named the same as a static
diff --git a/src/test/ui/issues/issue-23716.stderr b/src/test/ui/issues/issue-23716.stderr
index fd268c1b5a1..c175f197034 100644
--- a/src/test/ui/issues/issue-23716.stderr
+++ b/src/test/ui/issues/issue-23716.stderr
@@ -2,7 +2,7 @@ error[E0530]: function parameters cannot shadow statics
   --> $DIR/issue-23716.rs:13:8
    |
 LL | static foo: i32 = 0;
-   | -------------------- a static `foo` is defined here
+   | -------------------- the static `foo` is defined here
 LL | 
 LL | fn bar(foo: i32) {}
    |        ^^^ cannot be named the same as a static
@@ -11,7 +11,7 @@ error[E0530]: function parameters cannot shadow statics
   --> $DIR/issue-23716.rs:23:13
    |
 LL | use self::submod::answer;
-   |     -------------------- a static `answer` is imported here
+   |     -------------------- the static `answer` is imported here
 LL | 
 LL | fn question(answer: i32) {}
    |             ^^^^^^ cannot be named the same as a static
diff --git a/src/test/ui/issues/issue-27033.stderr b/src/test/ui/issues/issue-27033.stderr
index ba573c3eb6d..dfd635d36e8 100644
--- a/src/test/ui/issues/issue-27033.stderr
+++ b/src/test/ui/issues/issue-27033.stderr
@@ -8,7 +8,7 @@ error[E0530]: match bindings cannot shadow constants
   --> $DIR/issue-27033.rs:17:9
    |
 LL |     const C: u8 = 1;
-   |     ---------------- a constant `C` is defined here
+   |     ---------------- the constant `C` is defined here
 LL |     match 1 {
 LL |         C @ 2 => { //~ ERROR match bindings cannot shadow constant
    |         ^ cannot be named the same as a constant
diff --git a/src/test/ui/issues/issue-30560.rs b/src/test/ui/issues/issue-30560.rs
index 0b1afd75ca9..f033666220d 100644
--- a/src/test/ui/issues/issue-30560.rs
+++ b/src/test/ui/issues/issue-30560.rs
@@ -11,10 +11,10 @@
 type Alias = ();
 use Alias::*;
 //~^ ERROR unresolved import `Alias` [E0432]
-//~| Not a module `Alias`
+//~| not a module `Alias`
 use std::io::Result::*;
 //~^ ERROR unresolved import `std::io::Result` [E0432]
-//~| Not a module `Result`
+//~| not a module `Result`
 
 trait T {}
 use T::*; //~ ERROR items in traits are not importable
diff --git a/src/test/ui/issues/issue-30560.stderr b/src/test/ui/issues/issue-30560.stderr
index cb38c0dabe0..880c565cf9f 100644
--- a/src/test/ui/issues/issue-30560.stderr
+++ b/src/test/ui/issues/issue-30560.stderr
@@ -8,13 +8,13 @@ error[E0432]: unresolved import `Alias`
   --> $DIR/issue-30560.rs:12:5
    |
 LL | use Alias::*;
-   |     ^^^^^ Not a module `Alias`
+   |     ^^^^^ not a module `Alias`
 
 error[E0432]: unresolved import `std::io::Result`
   --> $DIR/issue-30560.rs:15:14
    |
 LL | use std::io::Result::*;
-   |              ^^^^^^ Not a module `Result`
+   |              ^^^^^^ not a module `Result`
 
 error: aborting due to 3 previous errors
 
diff --git a/src/test/ui/issues/issue-33293.rs b/src/test/ui/issues/issue-33293.rs
index bed577b8b9d..801ba7afcd6 100644
--- a/src/test/ui/issues/issue-33293.rs
+++ b/src/test/ui/issues/issue-33293.rs
@@ -11,6 +11,6 @@
 fn main() {
     match 0 {
         aaa::bbb(_) => ()
-        //~^ ERROR failed to resolve. Use of undeclared type or module `aaa`
+        //~^ ERROR failed to resolve: use of undeclared type or module `aaa`
     };
 }
diff --git a/src/test/ui/issues/issue-33293.stderr b/src/test/ui/issues/issue-33293.stderr
index e94979b6da4..dc288fa71ce 100644
--- a/src/test/ui/issues/issue-33293.stderr
+++ b/src/test/ui/issues/issue-33293.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve. Use of undeclared type or module `aaa`
+error[E0433]: failed to resolve: use of undeclared type or module `aaa`
   --> $DIR/issue-33293.rs:13:9
    |
 LL |         aaa::bbb(_) => ()
-   |         ^^^ Use of undeclared type or module `aaa`
+   |         ^^^ use of undeclared type or module `aaa`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-33464.stderr b/src/test/ui/issues/issue-33464.stderr
index b70fff01c9e..f41a3973625 100644
--- a/src/test/ui/issues/issue-33464.stderr
+++ b/src/test/ui/issues/issue-33464.stderr
@@ -2,19 +2,19 @@ error[E0432]: unresolved import `abc`
   --> $DIR/issue-33464.rs:13:5
    |
 LL | use abc::one_el;
-   |     ^^^ Maybe a missing `extern crate abc;`?
+   |     ^^^ maybe a missing `extern crate abc;`?
 
 error[E0432]: unresolved import `abc`
   --> $DIR/issue-33464.rs:15:5
    |
 LL | use abc::{a, bbb, cccccc};
-   |     ^^^ Maybe a missing `extern crate abc;`?
+   |     ^^^ maybe a missing `extern crate abc;`?
 
 error[E0432]: unresolved import `a_very_long_name`
   --> $DIR/issue-33464.rs:17:5
    |
 LL | use a_very_long_name::{el, el2};
-   |     ^^^^^^^^^^^^^^^^ Maybe a missing `extern crate a_very_long_name;`?
+   |     ^^^^^^^^^^^^^^^^ maybe a missing `extern crate a_very_long_name;`?
 
 error: aborting due to 3 previous errors
 
diff --git a/src/test/ui/issues/issue-34047.stderr b/src/test/ui/issues/issue-34047.stderr
index 10804cc6fff..10e4e9c1c12 100644
--- a/src/test/ui/issues/issue-34047.stderr
+++ b/src/test/ui/issues/issue-34047.stderr
@@ -2,7 +2,7 @@ error[E0530]: match bindings cannot shadow constants
   --> $DIR/issue-34047.rs:15:13
    |
 LL | const C: u8 = 0;
-   | ---------------- a constant `C` is defined here
+   | ---------------- the constant `C` is defined here
 ...
 LL |         mut C => {} //~ ERROR match bindings cannot shadow constants
    |             ^ cannot be named the same as a constant
diff --git a/src/test/ui/issues/issue-36881.stderr b/src/test/ui/issues/issue-36881.stderr
index 39132fde762..27effe9e342 100644
--- a/src/test/ui/issues/issue-36881.stderr
+++ b/src/test/ui/issues/issue-36881.stderr
@@ -2,7 +2,7 @@ error[E0432]: unresolved import `issue_36881_aux`
   --> $DIR/issue-36881.rs:16:9
    |
 LL |     use issue_36881_aux::Foo; //~ ERROR unresolved import
-   |         ^^^^^^^^^^^^^^^ Maybe a missing `extern crate issue_36881_aux;`?
+   |         ^^^^^^^^^^^^^^^ maybe a missing `extern crate issue_36881_aux;`?
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-37887.stderr b/src/test/ui/issues/issue-37887.stderr
index 8448466087d..48fb6c2e6fa 100644
--- a/src/test/ui/issues/issue-37887.stderr
+++ b/src/test/ui/issues/issue-37887.stderr
@@ -2,7 +2,7 @@ error[E0432]: unresolved import `libc`
   --> $DIR/issue-37887.rs:13:9
    |
 LL |     use libc::*; //~ ERROR unresolved import
-   |         ^^^^ Maybe a missing `extern crate libc;`?
+   |         ^^^^ maybe a missing `extern crate libc;`?
 
 error[E0658]: use of unstable library feature 'libc': use `libc` from crates.io (see issue #27783)
   --> $DIR/issue-37887.rs:12:5
diff --git a/src/test/ui/issues/issue-38857.rs b/src/test/ui/issues/issue-38857.rs
index b38b1b9fdc6..5217ddb9acb 100644
--- a/src/test/ui/issues/issue-38857.rs
+++ b/src/test/ui/issues/issue-38857.rs
@@ -10,6 +10,6 @@
 
 fn main() {
     let a = std::sys::imp::process::process_common::StdioPipes { ..panic!() };
-    //~^ ERROR failed to resolve. Could not find `imp` in `sys` [E0433]
+    //~^ ERROR failed to resolve: could not find `imp` in `sys` [E0433]
     //~^^ ERROR module `sys` is private [E0603]
 }
diff --git a/src/test/ui/issues/issue-38857.stderr b/src/test/ui/issues/issue-38857.stderr
index f6ed3202671..65026344feb 100644
--- a/src/test/ui/issues/issue-38857.stderr
+++ b/src/test/ui/issues/issue-38857.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve. Could not find `imp` in `sys`
+error[E0433]: failed to resolve: could not find `imp` in `sys`
   --> $DIR/issue-38857.rs:12:23
    |
 LL |     let a = std::sys::imp::process::process_common::StdioPipes { ..panic!() };
-   |                       ^^^ Could not find `imp` in `sys`
+   |                       ^^^ could not find `imp` in `sys`
 
 error[E0603]: module `sys` is private
   --> $DIR/issue-38857.rs:12:18
diff --git a/src/test/ui/keyword/keyword-super-as-identifier.rs b/src/test/ui/keyword/keyword-super-as-identifier.rs
index 54dac771f01..d8941f3e532 100644
--- a/src/test/ui/keyword/keyword-super-as-identifier.rs
+++ b/src/test/ui/keyword/keyword-super-as-identifier.rs
@@ -9,5 +9,5 @@
 // except according to those terms.
 
 fn main() {
-    let super = 22; //~ ERROR failed to resolve. There are too many initial `super`s
+    let super = 22; //~ ERROR failed to resolve: there are too many initial `super`s
 }
diff --git a/src/test/ui/keyword/keyword-super-as-identifier.stderr b/src/test/ui/keyword/keyword-super-as-identifier.stderr
index 649be45c224..9b665748794 100644
--- a/src/test/ui/keyword/keyword-super-as-identifier.stderr
+++ b/src/test/ui/keyword/keyword-super-as-identifier.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve. There are too many initial `super`s.
+error[E0433]: failed to resolve: there are too many initial `super`s.
   --> $DIR/keyword-super-as-identifier.rs:12:9
    |
-LL |     let super = 22; //~ ERROR failed to resolve. There are too many initial `super`s
-   |         ^^^^^ There are too many initial `super`s.
+LL |     let super = 22; //~ ERROR failed to resolve: there are too many initial `super`s
+   |         ^^^^^ there are too many initial `super`s.
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/keyword/keyword-super.rs b/src/test/ui/keyword/keyword-super.rs
index 02047bd639f..87640630818 100644
--- a/src/test/ui/keyword/keyword-super.rs
+++ b/src/test/ui/keyword/keyword-super.rs
@@ -9,5 +9,5 @@
 // except according to those terms.
 
 fn main() {
-    let super: isize; //~ ERROR failed to resolve. There are too many initial `super`s
+    let super: isize; //~ ERROR failed to resolve: there are too many initial `super`s
 }
diff --git a/src/test/ui/keyword/keyword-super.stderr b/src/test/ui/keyword/keyword-super.stderr
index ac692ad45d2..690b684c133 100644
--- a/src/test/ui/keyword/keyword-super.stderr
+++ b/src/test/ui/keyword/keyword-super.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve. There are too many initial `super`s.
+error[E0433]: failed to resolve: there are too many initial `super`s.
   --> $DIR/keyword-super.rs:12:9
    |
-LL |     let super: isize; //~ ERROR failed to resolve. There are too many initial `super`s
-   |         ^^^^^ There are too many initial `super`s.
+LL |     let super: isize; //~ ERROR failed to resolve: there are too many initial `super`s
+   |         ^^^^^ there are too many initial `super`s.
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/macros/ambiguity-legacy-vs-modern.stderr b/src/test/ui/macros/ambiguity-legacy-vs-modern.stderr
index b5e1e751737..2785594585d 100644
--- a/src/test/ui/macros/ambiguity-legacy-vs-modern.stderr
+++ b/src/test/ui/macros/ambiguity-legacy-vs-modern.stderr
@@ -1,32 +1,32 @@
-error[E0659]: `m` is ambiguous
+error[E0659]: `m` is ambiguous (`macro_rules` vs non-`macro_rules` from other module)
   --> $DIR/ambiguity-legacy-vs-modern.rs:31:9
    |
 LL |         m!() //~ ERROR `m` is ambiguous
    |         ^ ambiguous name
    |
-note: `m` could refer to the name defined here
+note: `m` could refer to the macro defined here
   --> $DIR/ambiguity-legacy-vs-modern.rs:26:5
    |
 LL |     macro_rules! m { () => (()) }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-note: `m` could also refer to the name defined here
+note: `m` could also refer to the macro defined here
   --> $DIR/ambiguity-legacy-vs-modern.rs:29:9
    |
 LL |         macro m() { 0 }
    |         ^^^^^^^^^^^^^^^
 
-error[E0659]: `m` is ambiguous
+error[E0659]: `m` is ambiguous (`macro_rules` vs non-`macro_rules` from other module)
   --> $DIR/ambiguity-legacy-vs-modern.rs:43:5
    |
 LL |     m!() //~ ERROR `m` is ambiguous
    |     ^ ambiguous name
    |
-note: `m` could refer to the name defined here
+note: `m` could refer to the macro defined here
   --> $DIR/ambiguity-legacy-vs-modern.rs:40:9
    |
 LL |         macro_rules! m { () => (()) }
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-note: `m` could also refer to the name defined here
+note: `m` could also refer to the macro defined here
   --> $DIR/ambiguity-legacy-vs-modern.rs:36:5
    |
 LL |     macro m() { 0 }
diff --git a/src/test/ui/macros/macro-inner-attributes.rs b/src/test/ui/macros/macro-inner-attributes.rs
index 1111b21d455..2a58fd55453 100644
--- a/src/test/ui/macros/macro-inner-attributes.rs
+++ b/src/test/ui/macros/macro-inner-attributes.rs
@@ -25,6 +25,6 @@ test!(b,
 #[qux]
 fn main() {
     a::bar();
-    //~^ ERROR failed to resolve. Use of undeclared type or module `a`
+    //~^ ERROR failed to resolve: use of undeclared type or module `a`
     b::bar();
 }
diff --git a/src/test/ui/macros/macro-inner-attributes.stderr b/src/test/ui/macros/macro-inner-attributes.stderr
index 11922bc448b..47d9469779b 100644
--- a/src/test/ui/macros/macro-inner-attributes.stderr
+++ b/src/test/ui/macros/macro-inner-attributes.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve. Use of undeclared type or module `a`
+error[E0433]: failed to resolve: use of undeclared type or module `a`
   --> $DIR/macro-inner-attributes.rs:27:5
    |
 LL |     a::bar();
-   |     ^ Use of undeclared type or module `a`
+   |     ^ use of undeclared type or module `a`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/macros/macro-path-prelude-fail-1.rs b/src/test/ui/macros/macro-path-prelude-fail-1.rs
index e1181eb741b..bdf3ac0f69f 100644
--- a/src/test/ui/macros/macro-path-prelude-fail-1.rs
+++ b/src/test/ui/macros/macro-path-prelude-fail-1.rs
@@ -12,8 +12,8 @@
 
 mod m {
     fn check() {
-        Vec::clone!(); //~ ERROR failed to resolve. Not a module `Vec`
-        u8::clone!(); //~ ERROR failed to resolve. Not a module `u8`
+        Vec::clone!(); //~ ERROR failed to resolve: not a module `Vec`
+        u8::clone!(); //~ ERROR failed to resolve: not a module `u8`
     }
 }
 
diff --git a/src/test/ui/macros/macro-path-prelude-fail-1.stderr b/src/test/ui/macros/macro-path-prelude-fail-1.stderr
index fc74937d912..590e4f0fd06 100644
--- a/src/test/ui/macros/macro-path-prelude-fail-1.stderr
+++ b/src/test/ui/macros/macro-path-prelude-fail-1.stderr
@@ -1,14 +1,14 @@
-error[E0433]: failed to resolve. Not a module `Vec`
+error[E0433]: failed to resolve: not a module `Vec`
   --> $DIR/macro-path-prelude-fail-1.rs:15:9
    |
-LL |         Vec::clone!(); //~ ERROR failed to resolve. Not a module `Vec`
-   |         ^^^ Not a module `Vec`
+LL |         Vec::clone!(); //~ ERROR failed to resolve: not a module `Vec`
+   |         ^^^ not a module `Vec`
 
-error[E0433]: failed to resolve. Not a module `u8`
+error[E0433]: failed to resolve: not a module `u8`
   --> $DIR/macro-path-prelude-fail-1.rs:16:9
    |
-LL |         u8::clone!(); //~ ERROR failed to resolve. Not a module `u8`
-   |         ^^ Not a module `u8`
+LL |         u8::clone!(); //~ ERROR failed to resolve: not a module `u8`
+   |         ^^ not a module `u8`
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/macros/macro-path-prelude-fail-2.rs b/src/test/ui/macros/macro-path-prelude-fail-2.rs
index 82258dac37b..e27c061e195 100644
--- a/src/test/ui/macros/macro-path-prelude-fail-2.rs
+++ b/src/test/ui/macros/macro-path-prelude-fail-2.rs
@@ -10,7 +10,7 @@
 
 mod m {
     fn check() {
-        Result::Ok!(); //~ ERROR fail to resolve non-ident macro path
+        Result::Ok!(); //~ ERROR failed to resolve: partially resolved path in a macro
     }
 }
 
diff --git a/src/test/ui/macros/macro-path-prelude-fail-2.stderr b/src/test/ui/macros/macro-path-prelude-fail-2.stderr
index 876ee2584e9..cf123f43fea 100644
--- a/src/test/ui/macros/macro-path-prelude-fail-2.stderr
+++ b/src/test/ui/macros/macro-path-prelude-fail-2.stderr
@@ -1,8 +1,9 @@
-error: fail to resolve non-ident macro path
+error[E0433]: failed to resolve: partially resolved path in a macro
   --> $DIR/macro-path-prelude-fail-2.rs:13:9
    |
-LL |         Result::Ok!(); //~ ERROR fail to resolve non-ident macro path
-   |         ^^^^^^^^^^
+LL |         Result::Ok!(); //~ ERROR failed to resolve: partially resolved path in a macro
+   |         ^^^^^^^^^^ partially resolved path in a macro
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0433`.
diff --git a/src/test/ui/macros/macro-path-prelude-shadowing.stderr b/src/test/ui/macros/macro-path-prelude-shadowing.stderr
index 688b9dc2797..904eed9f249 100644
--- a/src/test/ui/macros/macro-path-prelude-shadowing.stderr
+++ b/src/test/ui/macros/macro-path-prelude-shadowing.stderr
@@ -1,16 +1,17 @@
-error[E0659]: `std` is ambiguous
+error[E0659]: `std` is ambiguous (glob import vs any other name from outer scope during import/macro resolution)
   --> $DIR/macro-path-prelude-shadowing.rs:39:9
    |
 LL |         std::panic!(); //~ ERROR `std` is ambiguous
    |         ^^^ ambiguous name
    |
-note: `std` could refer to the name imported here
+   = note: `std` could refer to a built-in extern crate
+note: `std` could also refer to the module imported here
   --> $DIR/macro-path-prelude-shadowing.rs:37:9
    |
 LL |     use m2::*; // glob-import user-defined `std`
    |         ^^^^^
-note: `std` could also refer to the name defined here
-   = note: consider adding an explicit import of `std` to disambiguate
+   = help: consider adding an explicit import of `std` to disambiguate
+   = help: or use `self::std` to refer to this module unambiguously
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/macros/macro-shadowing.stderr b/src/test/ui/macros/macro-shadowing.stderr
index d996f3a7041..6985dfcc6c2 100644
--- a/src/test/ui/macros/macro-shadowing.stderr
+++ b/src/test/ui/macros/macro-shadowing.stderr
@@ -9,13 +9,13 @@ LL | m1!();
    |
    = note: macro-expanded `#[macro_use]`s may not shadow existing macros (see RFC 1560)
 
-error[E0659]: `foo` is ambiguous
+error[E0659]: `foo` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/macro-shadowing.rs:27:1
    |
 LL | foo!(); //~ ERROR `foo` is ambiguous
    | ^^^ ambiguous name
    |
-note: `foo` could refer to the name defined here
+note: `foo` could refer to the macro defined here
   --> $DIR/macro-shadowing.rs:20:5
    |
 LL |     macro_rules! foo { () => {} }
@@ -23,12 +23,11 @@ LL |     macro_rules! foo { () => {} }
 ...
 LL | m1!();
    | ------ in this macro invocation
-note: `foo` could also refer to the name defined here
+note: `foo` could also refer to the macro defined here
   --> $DIR/macro-shadowing.rs:15:1
    |
 LL | macro_rules! foo { () => {} }
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   = note: macro-expanded macros do not shadow
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/macros/macro_path_as_generic_bound.stderr b/src/test/ui/macros/macro_path_as_generic_bound.stderr
index 0f9f0607c5b..8b4fe9f200d 100644
--- a/src/test/ui/macros/macro_path_as_generic_bound.stderr
+++ b/src/test/ui/macros/macro_path_as_generic_bound.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve. Use of undeclared type or module `m`
+error[E0433]: failed to resolve: use of undeclared type or module `m`
   --> $DIR/macro_path_as_generic_bound.rs:17:6
    |
 LL | foo!(m::m2::A); //~ ERROR failed to resolve
-   |      ^ Use of undeclared type or module `m`
+   |      ^ use of undeclared type or module `m`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/macros/restricted-shadowing-legacy.stderr b/src/test/ui/macros/restricted-shadowing-legacy.stderr
index 9e0d40c44b6..2135d63c80e 100644
--- a/src/test/ui/macros/restricted-shadowing-legacy.stderr
+++ b/src/test/ui/macros/restricted-shadowing-legacy.stderr
@@ -1,10 +1,10 @@
-error[E0659]: `m` is ambiguous
+error[E0659]: `m` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/restricted-shadowing-legacy.rs:101:13
    |
 LL |             m!(); //~ ERROR `m` is ambiguous
    |             ^ ambiguous name
    |
-note: `m` could refer to the name defined here
+note: `m` could refer to the macro defined here
   --> $DIR/restricted-shadowing-legacy.rs:88:9
    |
 LL |         macro_rules! m { () => { Right } }
@@ -12,7 +12,7 @@ LL |         macro_rules! m { () => { Right } }
 ...
 LL | include!();
    | ----------- in this macro invocation
-note: `m` could also refer to the name defined here
+note: `m` could also refer to the macro defined here
   --> $DIR/restricted-shadowing-legacy.rs:97:9
    |
 LL |         macro_rules! m { () => {} }
@@ -20,15 +20,14 @@ LL |         macro_rules! m { () => {} }
 ...
 LL | include!();
    | ----------- in this macro invocation
-   = note: macro-expanded macros do not shadow
 
-error[E0659]: `m` is ambiguous
+error[E0659]: `m` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/restricted-shadowing-legacy.rs:139:42
    |
 LL |         macro_rules! gen_invoc { () => { m!() } } //~ ERROR `m` is ambiguous
    |                                          ^ ambiguous name
    |
-note: `m` could refer to the name defined here
+note: `m` could refer to the macro defined here
   --> $DIR/restricted-shadowing-legacy.rs:88:9
    |
 LL |         macro_rules! m { () => { Right } }
@@ -36,7 +35,7 @@ LL |         macro_rules! m { () => { Right } }
 ...
 LL | include!();
    | ----------- in this macro invocation
-note: `m` could also refer to the name defined here
+note: `m` could also refer to the macro defined here
   --> $DIR/restricted-shadowing-legacy.rs:135:9
    |
 LL |         macro_rules! m { () => {} }
@@ -44,15 +43,14 @@ LL |         macro_rules! m { () => {} }
 ...
 LL | include!();
    | ----------- in this macro invocation
-   = note: macro-expanded macros do not shadow
 
-error[E0659]: `m` is ambiguous
+error[E0659]: `m` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/restricted-shadowing-legacy.rs:148:9
    |
 LL |         m!(); //~ ERROR `m` is ambiguous
    |         ^ ambiguous name
    |
-note: `m` could refer to the name defined here
+note: `m` could refer to the macro defined here
   --> $DIR/restricted-shadowing-legacy.rs:88:9
    |
 LL |         macro_rules! m { () => { Right } }
@@ -60,7 +58,7 @@ LL |         macro_rules! m { () => { Right } }
 ...
 LL | include!();
    | ----------- in this macro invocation
-note: `m` could also refer to the name defined here
+note: `m` could also refer to the macro defined here
   --> $DIR/restricted-shadowing-legacy.rs:144:9
    |
 LL |         macro_rules! m { () => {} }
@@ -68,15 +66,14 @@ LL |         macro_rules! m { () => {} }
 ...
 LL | include!();
    | ----------- in this macro invocation
-   = note: macro-expanded macros do not shadow
 
-error[E0659]: `m` is ambiguous
+error[E0659]: `m` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/restricted-shadowing-legacy.rs:164:9
    |
 LL |         m!(); //~ ERROR `m` is ambiguous
    |         ^ ambiguous name
    |
-note: `m` could refer to the name defined here
+note: `m` could refer to the macro defined here
   --> $DIR/restricted-shadowing-legacy.rs:88:9
    |
 LL |         macro_rules! m { () => { Right } }
@@ -84,7 +81,7 @@ LL |         macro_rules! m { () => { Right } }
 ...
 LL | include!();
    | ----------- in this macro invocation
-note: `m` could also refer to the name defined here
+note: `m` could also refer to the macro defined here
   --> $DIR/restricted-shadowing-legacy.rs:85:9
    |
 LL |         macro_rules! m { () => { Wrong } }
@@ -92,15 +89,14 @@ LL |         macro_rules! m { () => { Wrong } }
 ...
 LL | include!();
    | ----------- in this macro invocation
-   = note: macro-expanded macros do not shadow
 
-error[E0659]: `m` is ambiguous
+error[E0659]: `m` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/restricted-shadowing-legacy.rs:180:13
    |
 LL |             m!(); //~ ERROR `m` is ambiguous
    |             ^ ambiguous name
    |
-note: `m` could refer to the name defined here
+note: `m` could refer to the macro defined here
   --> $DIR/restricted-shadowing-legacy.rs:88:9
    |
 LL |         macro_rules! m { () => { Right } }
@@ -108,7 +104,7 @@ LL |         macro_rules! m { () => { Right } }
 ...
 LL | include!();
    | ----------- in this macro invocation
-note: `m` could also refer to the name defined here
+note: `m` could also refer to the macro defined here
   --> $DIR/restricted-shadowing-legacy.rs:85:9
    |
 LL |         macro_rules! m { () => { Wrong } }
@@ -116,15 +112,14 @@ LL |         macro_rules! m { () => { Wrong } }
 ...
 LL | include!();
    | ----------- in this macro invocation
-   = note: macro-expanded macros do not shadow
 
-error[E0659]: `m` is ambiguous
+error[E0659]: `m` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/restricted-shadowing-legacy.rs:218:42
    |
 LL |         macro_rules! gen_invoc { () => { m!() } } //~ ERROR `m` is ambiguous
    |                                          ^ ambiguous name
    |
-note: `m` could refer to the name defined here
+note: `m` could refer to the macro defined here
   --> $DIR/restricted-shadowing-legacy.rs:88:9
    |
 LL |         macro_rules! m { () => { Right } }
@@ -132,7 +127,7 @@ LL |         macro_rules! m { () => { Right } }
 ...
 LL | include!();
    | ----------- in this macro invocation
-note: `m` could also refer to the name defined here
+note: `m` could also refer to the macro defined here
   --> $DIR/restricted-shadowing-legacy.rs:85:9
    |
 LL |         macro_rules! m { () => { Wrong } }
@@ -140,15 +135,14 @@ LL |         macro_rules! m { () => { Wrong } }
 ...
 LL | include!();
    | ----------- in this macro invocation
-   = note: macro-expanded macros do not shadow
 
-error[E0659]: `m` is ambiguous
+error[E0659]: `m` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/restricted-shadowing-legacy.rs:232:9
    |
 LL |         m!(); //~ ERROR `m` is ambiguous
    |         ^ ambiguous name
    |
-note: `m` could refer to the name defined here
+note: `m` could refer to the macro defined here
   --> $DIR/restricted-shadowing-legacy.rs:88:9
    |
 LL |         macro_rules! m { () => { Right } }
@@ -156,7 +150,7 @@ LL |         macro_rules! m { () => { Right } }
 ...
 LL | include!();
    | ----------- in this macro invocation
-note: `m` could also refer to the name defined here
+note: `m` could also refer to the macro defined here
   --> $DIR/restricted-shadowing-legacy.rs:227:13
    |
 LL |             macro_rules! m { () => {} }
@@ -164,15 +158,14 @@ LL |             macro_rules! m { () => {} }
 ...
 LL | include!();
    | ----------- in this macro invocation
-   = note: macro-expanded macros do not shadow
 
-error[E0659]: `m` is ambiguous
+error[E0659]: `m` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/restricted-shadowing-legacy.rs:262:42
    |
 LL |         macro_rules! gen_invoc { () => { m!() } } //~ ERROR `m` is ambiguous
    |                                          ^ ambiguous name
    |
-note: `m` could refer to the name defined here
+note: `m` could refer to the macro defined here
   --> $DIR/restricted-shadowing-legacy.rs:88:9
    |
 LL |         macro_rules! m { () => { Right } }
@@ -180,7 +173,7 @@ LL |         macro_rules! m { () => { Right } }
 ...
 LL | include!();
    | ----------- in this macro invocation
-note: `m` could also refer to the name defined here
+note: `m` could also refer to the macro defined here
   --> $DIR/restricted-shadowing-legacy.rs:257:13
    |
 LL |             macro_rules! m { () => {} }
@@ -188,7 +181,6 @@ LL |             macro_rules! m { () => {} }
 ...
 LL | include!();
    | ----------- in this macro invocation
-   = note: macro-expanded macros do not shadow
 
 error: aborting due to 8 previous errors
 
diff --git a/src/test/ui/macros/restricted-shadowing-modern.stderr b/src/test/ui/macros/restricted-shadowing-modern.stderr
index 0462438be78..2449e8512d3 100644
--- a/src/test/ui/macros/restricted-shadowing-modern.stderr
+++ b/src/test/ui/macros/restricted-shadowing-modern.stderr
@@ -1,10 +1,10 @@
-error[E0659]: `m` is ambiguous
+error[E0659]: `m` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/restricted-shadowing-modern.rs:106:17
    |
 LL |                 m!(); //~ ERROR `m` is ambiguous
    |                 ^ ambiguous name
    |
-note: `m` could refer to the name defined here
+note: `m` could refer to the macro defined here
   --> $DIR/restricted-shadowing-modern.rs:91:9
    |
 LL |         macro m() { Right }
@@ -12,7 +12,7 @@ LL |         macro m() { Right }
 ...
 LL | include!();
    | ----------- in this macro invocation
-note: `m` could also refer to the name defined here
+note: `m` could also refer to the macro defined here
   --> $DIR/restricted-shadowing-modern.rs:101:9
    |
 LL |         macro m() {}
@@ -20,15 +20,14 @@ LL |         macro m() {}
 ...
 LL | include!();
    | ----------- in this macro invocation
-   = note: macro-expanded macros do not shadow
 
-error[E0659]: `m` is ambiguous
+error[E0659]: `m` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/restricted-shadowing-modern.rs:149:33
    |
 LL |             macro gen_invoc() { m!() } //~ ERROR `m` is ambiguous
    |                                 ^ ambiguous name
    |
-note: `m` could refer to the name defined here
+note: `m` could refer to the macro defined here
   --> $DIR/restricted-shadowing-modern.rs:91:9
    |
 LL |         macro m() { Right }
@@ -36,7 +35,7 @@ LL |         macro m() { Right }
 ...
 LL | include!();
    | ----------- in this macro invocation
-note: `m` could also refer to the name defined here
+note: `m` could also refer to the macro defined here
   --> $DIR/restricted-shadowing-modern.rs:145:9
    |
 LL |         macro m() {}
@@ -44,15 +43,14 @@ LL |         macro m() {}
 ...
 LL | include!();
    | ----------- in this macro invocation
-   = note: macro-expanded macros do not shadow
 
-error[E0659]: `m` is ambiguous
+error[E0659]: `m` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/restricted-shadowing-modern.rs:158:13
    |
 LL |             m!(); //~ ERROR `m` is ambiguous
    |             ^ ambiguous name
    |
-note: `m` could refer to the name defined here
+note: `m` could refer to the macro defined here
   --> $DIR/restricted-shadowing-modern.rs:91:9
    |
 LL |         macro m() { Right }
@@ -60,7 +58,7 @@ LL |         macro m() { Right }
 ...
 LL | include!();
    | ----------- in this macro invocation
-note: `m` could also refer to the name defined here
+note: `m` could also refer to the macro defined here
   --> $DIR/restricted-shadowing-modern.rs:155:9
    |
 LL |         macro m() {}
@@ -68,15 +66,14 @@ LL |         macro m() {}
 ...
 LL | include!();
    | ----------- in this macro invocation
-   = note: macro-expanded macros do not shadow
 
-error[E0659]: `m` is ambiguous
+error[E0659]: `m` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/restricted-shadowing-modern.rs:174:13
    |
 LL |             m!(); //~ ERROR `m` is ambiguous
    |             ^ ambiguous name
    |
-note: `m` could refer to the name defined here
+note: `m` could refer to the macro defined here
   --> $DIR/restricted-shadowing-modern.rs:91:9
    |
 LL |         macro m() { Right }
@@ -84,7 +81,7 @@ LL |         macro m() { Right }
 ...
 LL | include!();
    | ----------- in this macro invocation
-note: `m` could also refer to the name defined here
+note: `m` could also refer to the macro defined here
   --> $DIR/restricted-shadowing-modern.rs:87:9
    |
 LL |         macro m() { Wrong }
@@ -92,15 +89,14 @@ LL |         macro m() { Wrong }
 ...
 LL | include!();
    | ----------- in this macro invocation
-   = note: macro-expanded macros do not shadow
 
-error[E0659]: `m` is ambiguous
+error[E0659]: `m` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/restricted-shadowing-modern.rs:192:17
    |
 LL |                 m!(); //~ ERROR `m` is ambiguous
    |                 ^ ambiguous name
    |
-note: `m` could refer to the name defined here
+note: `m` could refer to the macro defined here
   --> $DIR/restricted-shadowing-modern.rs:91:9
    |
 LL |         macro m() { Right }
@@ -108,7 +104,7 @@ LL |         macro m() { Right }
 ...
 LL | include!();
    | ----------- in this macro invocation
-note: `m` could also refer to the name defined here
+note: `m` could also refer to the macro defined here
   --> $DIR/restricted-shadowing-modern.rs:87:9
    |
 LL |         macro m() { Wrong }
@@ -116,15 +112,14 @@ LL |         macro m() { Wrong }
 ...
 LL | include!();
    | ----------- in this macro invocation
-   = note: macro-expanded macros do not shadow
 
-error[E0659]: `m` is ambiguous
+error[E0659]: `m` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/restricted-shadowing-modern.rs:235:33
    |
 LL |             macro gen_invoc() { m!() } //~ ERROR `m` is ambiguous
    |                                 ^ ambiguous name
    |
-note: `m` could refer to the name defined here
+note: `m` could refer to the macro defined here
   --> $DIR/restricted-shadowing-modern.rs:91:9
    |
 LL |         macro m() { Right }
@@ -132,7 +127,7 @@ LL |         macro m() { Right }
 ...
 LL | include!();
    | ----------- in this macro invocation
-note: `m` could also refer to the name defined here
+note: `m` could also refer to the macro defined here
   --> $DIR/restricted-shadowing-modern.rs:87:9
    |
 LL |         macro m() { Wrong }
@@ -140,7 +135,6 @@ LL |         macro m() { Wrong }
 ...
 LL | include!();
    | ----------- in this macro invocation
-   = note: macro-expanded macros do not shadow
 
 error: aborting due to 6 previous errors
 
diff --git a/src/test/ui/out-of-order-shadowing.stderr b/src/test/ui/out-of-order-shadowing.stderr
index d96a802cb3f..4696e205728 100644
--- a/src/test/ui/out-of-order-shadowing.stderr
+++ b/src/test/ui/out-of-order-shadowing.stderr
@@ -1,20 +1,19 @@
-error[E0659]: `bar` is ambiguous
+error[E0659]: `bar` is ambiguous (macro-expanded name vs less macro-expanded name from outer scope during import/macro resolution)
   --> $DIR/out-of-order-shadowing.rs:15:1
    |
 LL | bar!(); //~ ERROR `bar` is ambiguous
    | ^^^ ambiguous name
    |
-note: `bar` could refer to the name defined here
+note: `bar` could refer to the macro defined here
   --> $DIR/out-of-order-shadowing.rs:14:1
    |
 LL | define_macro!(bar);
    | ^^^^^^^^^^^^^^^^^^^
-note: `bar` could also refer to the name defined here
+note: `bar` could also refer to the macro defined here
   --> $DIR/out-of-order-shadowing.rs:13:1
    |
 LL | macro_rules! bar { () => {} }
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   = note: macro-expanded macros do not shadow
    = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
 
 error: aborting due to previous error
diff --git a/src/test/ui/pattern/pat-shadow-in-nested-binding.stderr b/src/test/ui/pattern/pat-shadow-in-nested-binding.stderr
index 9dd6a318e98..994c78d575e 100644
--- a/src/test/ui/pattern/pat-shadow-in-nested-binding.stderr
+++ b/src/test/ui/pattern/pat-shadow-in-nested-binding.stderr
@@ -2,7 +2,7 @@ error[E0530]: let bindings cannot shadow tuple structs
   --> $DIR/pat-shadow-in-nested-binding.rs:14:10
    |
 LL | struct foo(usize);
-   | ------------------ a tuple struct `foo` is defined here
+   | ------------------ the tuple struct `foo` is defined here
 ...
 LL |     let (foo, _) = (2, 3); //~ ERROR let bindings cannot shadow tuple structs
    |          ^^^ cannot be named the same as a tuple struct
diff --git a/src/test/ui/pattern/pattern-binding-disambiguation.stderr b/src/test/ui/pattern/pattern-binding-disambiguation.stderr
index 7acdb07e10d..5d14610b8a1 100644
--- a/src/test/ui/pattern/pattern-binding-disambiguation.stderr
+++ b/src/test/ui/pattern/pattern-binding-disambiguation.stderr
@@ -2,7 +2,7 @@ error[E0530]: match bindings cannot shadow tuple structs
   --> $DIR/pattern-binding-disambiguation.rs:34:9
    |
 LL | struct TupleStruct();
-   | --------------------- a tuple struct `TupleStruct` is defined here
+   | --------------------- the tuple struct `TupleStruct` is defined here
 ...
 LL |         TupleStruct => {} //~ ERROR match bindings cannot shadow tuple structs
    |         ^^^^^^^^^^^ cannot be named the same as a tuple struct
@@ -11,7 +11,7 @@ error[E0530]: match bindings cannot shadow tuple variants
   --> $DIR/pattern-binding-disambiguation.rs:43:9
    |
 LL | use E::*;
-   |     ---- a tuple variant `TupleVariant` is imported here
+   |     ---- the tuple variant `TupleVariant` is imported here
 ...
 LL |         TupleVariant => {} //~ ERROR match bindings cannot shadow tuple variants
    |         ^^^^^^^^^^^^ cannot be named the same as a tuple variant
@@ -20,7 +20,7 @@ error[E0530]: match bindings cannot shadow struct variants
   --> $DIR/pattern-binding-disambiguation.rs:46:9
    |
 LL | use E::*;
-   |     ---- a struct variant `BracedVariant` is imported here
+   |     ---- the struct variant `BracedVariant` is imported here
 ...
 LL |         BracedVariant => {} //~ ERROR match bindings cannot shadow struct variants
    |         ^^^^^^^^^^^^^ cannot be named the same as a struct variant
@@ -29,7 +29,7 @@ error[E0530]: match bindings cannot shadow statics
   --> $DIR/pattern-binding-disambiguation.rs:52:9
    |
 LL | static STATIC: () = ();
-   | ----------------------- a static `STATIC` is defined here
+   | ----------------------- the static `STATIC` is defined here
 ...
 LL |         STATIC => {} //~ ERROR match bindings cannot shadow statics
    |         ^^^^^^ cannot be named the same as a static
@@ -38,7 +38,7 @@ error[E0530]: let bindings cannot shadow tuple structs
   --> $DIR/pattern-binding-disambiguation.rs:59:9
    |
 LL | struct TupleStruct();
-   | --------------------- a tuple struct `TupleStruct` is defined here
+   | --------------------- the tuple struct `TupleStruct` is defined here
 ...
 LL |     let TupleStruct = doesnt_matter; //~ ERROR let bindings cannot shadow tuple structs
    |         ^^^^^^^^^^^ cannot be named the same as a tuple struct
@@ -47,7 +47,7 @@ error[E0530]: let bindings cannot shadow tuple variants
   --> $DIR/pattern-binding-disambiguation.rs:62:9
    |
 LL | use E::*;
-   |     ---- a tuple variant `TupleVariant` is imported here
+   |     ---- the tuple variant `TupleVariant` is imported here
 ...
 LL |     let TupleVariant = doesnt_matter; //~ ERROR let bindings cannot shadow tuple variants
    |         ^^^^^^^^^^^^ cannot be named the same as a tuple variant
@@ -56,7 +56,7 @@ error[E0530]: let bindings cannot shadow struct variants
   --> $DIR/pattern-binding-disambiguation.rs:63:9
    |
 LL | use E::*;
-   |     ---- a struct variant `BracedVariant` is imported here
+   |     ---- the struct variant `BracedVariant` is imported here
 ...
 LL |     let BracedVariant = doesnt_matter; //~ ERROR let bindings cannot shadow struct variants
    |         ^^^^^^^^^^^^^ cannot be named the same as a struct variant
@@ -65,7 +65,7 @@ error[E0530]: let bindings cannot shadow statics
   --> $DIR/pattern-binding-disambiguation.rs:65:9
    |
 LL | static STATIC: () = ();
-   | ----------------------- a static `STATIC` is defined here
+   | ----------------------- the static `STATIC` is defined here
 ...
 LL |     let STATIC = doesnt_matter; //~ ERROR let bindings cannot shadow statics
    |         ^^^^^^ cannot be named the same as a static
diff --git a/src/test/ui/pattern/pattern-error-continue.rs b/src/test/ui/pattern/pattern-error-continue.rs
index e63b84594aa..c544ca4e304 100644
--- a/src/test/ui/pattern/pattern-error-continue.rs
+++ b/src/test/ui/pattern/pattern-error-continue.rs
@@ -42,6 +42,6 @@ fn main() {
     //~| expected char, found bool
 
     match () {
-        E::V => {} //~ ERROR failed to resolve. Use of undeclared type or module `E`
+        E::V => {} //~ ERROR failed to resolve: use of undeclared type or module `E`
     }
 }
diff --git a/src/test/ui/pattern/pattern-error-continue.stderr b/src/test/ui/pattern/pattern-error-continue.stderr
index b24366c48bc..f2c35ef872d 100644
--- a/src/test/ui/pattern/pattern-error-continue.stderr
+++ b/src/test/ui/pattern/pattern-error-continue.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve. Use of undeclared type or module `E`
+error[E0433]: failed to resolve: use of undeclared type or module `E`
   --> $DIR/pattern-error-continue.rs:45:9
    |
-LL |         E::V => {} //~ ERROR failed to resolve. Use of undeclared type or module `E`
-   |         ^ Use of undeclared type or module `E`
+LL |         E::V => {} //~ ERROR failed to resolve: use of undeclared type or module `E`
+   |         ^ use of undeclared type or module `E`
 
 error[E0532]: expected tuple struct/variant, found unit variant `A::D`
   --> $DIR/pattern-error-continue.rs:28:9
diff --git a/src/test/ui/privacy/decl-macro.rs b/src/test/ui/privacy/decl-macro.rs
new file mode 100644
index 00000000000..1eb49bd5301
--- /dev/null
+++ b/src/test/ui/privacy/decl-macro.rs
@@ -0,0 +1,9 @@
+#![feature(decl_macro)]
+
+mod m {
+    macro mac() {}
+}
+
+fn main() {
+    m::mac!(); //~ ERROR macro `mac` is private
+}
diff --git a/src/test/ui/privacy/decl-macro.stderr b/src/test/ui/privacy/decl-macro.stderr
new file mode 100644
index 00000000000..c8b043d1b5f
--- /dev/null
+++ b/src/test/ui/privacy/decl-macro.stderr
@@ -0,0 +1,9 @@
+error[E0603]: macro `mac` is private
+  --> $DIR/decl-macro.rs:8:8
+   |
+LL |     m::mac!(); //~ ERROR macro `mac` is private
+   |        ^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0603`.
diff --git a/src/test/ui/privacy/restricted/test.rs b/src/test/ui/privacy/restricted/test.rs
index 8c1d609e244..2b2d9b76bdd 100644
--- a/src/test/ui/privacy/restricted/test.rs
+++ b/src/test/ui/privacy/restricted/test.rs
@@ -57,6 +57,6 @@ fn main() {
 }
 
 mod pathological {
-    pub(in bad::path) mod m1 {} //~ ERROR failed to resolve. Maybe a missing `extern crate bad;`?
+    pub(in bad::path) mod m1 {} //~ ERROR failed to resolve: maybe a missing `extern crate bad;`?
     pub(in foo) mod m2 {} //~ ERROR visibilities can only be restricted to ancestor modules
 }
diff --git a/src/test/ui/privacy/restricted/test.stderr b/src/test/ui/privacy/restricted/test.stderr
index afc3ee2db4b..01e224910a5 100644
--- a/src/test/ui/privacy/restricted/test.stderr
+++ b/src/test/ui/privacy/restricted/test.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve. Maybe a missing `extern crate bad;`?
+error[E0433]: failed to resolve: maybe a missing `extern crate bad;`?
   --> $DIR/test.rs:60:12
    |
-LL |     pub(in bad::path) mod m1 {} //~ ERROR failed to resolve. Maybe a missing `extern crate bad;`?
-   |            ^^^ Maybe a missing `extern crate bad;`?
+LL |     pub(in bad::path) mod m1 {} //~ ERROR failed to resolve: maybe a missing `extern crate bad;`?
+   |            ^^^ maybe a missing `extern crate bad;`?
 
 error: visibilities can only be restricted to ancestor modules
   --> $DIR/test.rs:61:12
diff --git a/src/test/ui/resolve/resolve-variant-assoc-item.rs b/src/test/ui/resolve/resolve-variant-assoc-item.rs
index 869eed5a8d7..01f493e954b 100644
--- a/src/test/ui/resolve/resolve-variant-assoc-item.rs
+++ b/src/test/ui/resolve/resolve-variant-assoc-item.rs
@@ -12,6 +12,6 @@ enum E { V }
 use E::V;
 
 fn main() {
-    E::V::associated_item; //~ ERROR failed to resolve. Not a module `V`
-    V::associated_item; //~ ERROR failed to resolve. Not a module `V`
+    E::V::associated_item; //~ ERROR failed to resolve: not a module `V`
+    V::associated_item; //~ ERROR failed to resolve: not a module `V`
 }
diff --git a/src/test/ui/resolve/resolve-variant-assoc-item.stderr b/src/test/ui/resolve/resolve-variant-assoc-item.stderr
index a80a7c39249..ef2d0a71b5b 100644
--- a/src/test/ui/resolve/resolve-variant-assoc-item.stderr
+++ b/src/test/ui/resolve/resolve-variant-assoc-item.stderr
@@ -1,14 +1,14 @@
-error[E0433]: failed to resolve. Not a module `V`
+error[E0433]: failed to resolve: not a module `V`
   --> $DIR/resolve-variant-assoc-item.rs:15:8
    |
-LL |     E::V::associated_item; //~ ERROR failed to resolve. Not a module `V`
-   |        ^ Not a module `V`
+LL |     E::V::associated_item; //~ ERROR failed to resolve: not a module `V`
+   |        ^ not a module `V`
 
-error[E0433]: failed to resolve. Not a module `V`
+error[E0433]: failed to resolve: not a module `V`
   --> $DIR/resolve-variant-assoc-item.rs:16:5
    |
-LL |     V::associated_item; //~ ERROR failed to resolve. Not a module `V`
-   |     ^ Not a module `V`
+LL |     V::associated_item; //~ ERROR failed to resolve: not a module `V`
+   |     ^ not a module `V`
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/resolve_self_super_hint.rs b/src/test/ui/resolve_self_super_hint.rs
index a30e73cf02d..2ce2d765832 100644
--- a/src/test/ui/resolve_self_super_hint.rs
+++ b/src/test/ui/resolve_self_super_hint.rs
@@ -15,19 +15,19 @@ mod a {
     extern crate alloc;
     use alloc::HashMap;
     //~^ ERROR unresolved import `alloc` [E0432]
-    //~| Did you mean `self::alloc`?
+    //~| did you mean `self::alloc`?
     mod b {
         use alloc::HashMap;
         //~^ ERROR unresolved import `alloc` [E0432]
-        //~| Did you mean `super::alloc`?
+        //~| did you mean `super::alloc`?
         mod c {
             use alloc::HashMap;
             //~^ ERROR unresolved import `alloc` [E0432]
-            //~| Did you mean `std::alloc`?
+            //~| did you mean `a::alloc`?
             mod d {
                 use alloc::HashMap;
                 //~^ ERROR unresolved import `alloc` [E0432]
-                //~| Did you mean `std::alloc`?
+                //~| did you mean `a::alloc`?
             }
         }
     }
diff --git a/src/test/ui/resolve_self_super_hint.stderr b/src/test/ui/resolve_self_super_hint.stderr
index b58a23724e4..613107712b2 100644
--- a/src/test/ui/resolve_self_super_hint.stderr
+++ b/src/test/ui/resolve_self_super_hint.stderr
@@ -2,25 +2,25 @@ error[E0432]: unresolved import `alloc`
   --> $DIR/resolve_self_super_hint.rs:16:9
    |
 LL |     use alloc::HashMap;
-   |         ^^^^^ Did you mean `self::alloc`?
+   |         ^^^^^ did you mean `self::alloc`?
 
 error[E0432]: unresolved import `alloc`
   --> $DIR/resolve_self_super_hint.rs:20:13
    |
 LL |         use alloc::HashMap;
-   |             ^^^^^ Did you mean `super::alloc`?
+   |             ^^^^^ did you mean `super::alloc`?
 
 error[E0432]: unresolved import `alloc`
   --> $DIR/resolve_self_super_hint.rs:24:17
    |
 LL |             use alloc::HashMap;
-   |                 ^^^^^ Did you mean `std::alloc`?
+   |                 ^^^^^ did you mean `a::alloc`?
 
 error[E0432]: unresolved import `alloc`
   --> $DIR/resolve_self_super_hint.rs:28:21
    |
 LL |                 use alloc::HashMap;
-   |                     ^^^^^ Did you mean `std::alloc`?
+   |                     ^^^^^ did you mean `a::alloc`?
 
 error: aborting due to 4 previous errors
 
diff --git a/src/test/ui/rfc-2126-crate-paths/crate-path-non-absolute.stderr b/src/test/ui/rfc-2126-crate-paths/crate-path-non-absolute.stderr
index f16c8496077..2751d8cb285 100644
--- a/src/test/ui/rfc-2126-crate-paths/crate-path-non-absolute.stderr
+++ b/src/test/ui/rfc-2126-crate-paths/crate-path-non-absolute.stderr
@@ -1,10 +1,10 @@
-error[E0433]: failed to resolve. `crate` in paths can only be used in start position
+error[E0433]: failed to resolve: `crate` in paths can only be used in start position
   --> $DIR/crate-path-non-absolute.rs:17:22
    |
 LL |         let s = ::m::crate::S; //~ ERROR failed to resolve
    |                      ^^^^^ `crate` in paths can only be used in start position
 
-error[E0433]: failed to resolve. global paths cannot start with `crate`
+error[E0433]: failed to resolve: global paths cannot start with `crate`
   --> $DIR/crate-path-non-absolute.rs:18:20
    |
 LL |         let s1 = ::crate::S; //~ ERROR failed to resolve
diff --git a/src/test/ui/rfc-2126-extern-absolute-paths/non-existent-1.stderr b/src/test/ui/rfc-2126-extern-absolute-paths/non-existent-1.stderr
index 1a8ceec5dac..39b2db7a19f 100644
--- a/src/test/ui/rfc-2126-extern-absolute-paths/non-existent-1.stderr
+++ b/src/test/ui/rfc-2126-extern-absolute-paths/non-existent-1.stderr
@@ -2,7 +2,7 @@ error[E0432]: unresolved import `xcrate`
   --> $DIR/non-existent-1.rs:13:5
    |
 LL | use xcrate::S; //~ ERROR unresolved import `xcrate`
-   |     ^^^^^^ Could not find `xcrate` in `{{root}}`
+   |     ^^^^^^ use of undeclared type or module `xcrate`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/rfc-2126-extern-absolute-paths/non-existent-2.rs b/src/test/ui/rfc-2126-extern-absolute-paths/non-existent-2.rs
index 41adb974f21..a07c3f17d6f 100644
--- a/src/test/ui/rfc-2126-extern-absolute-paths/non-existent-2.rs
+++ b/src/test/ui/rfc-2126-extern-absolute-paths/non-existent-2.rs
@@ -12,5 +12,5 @@
 
 fn main() {
     let s = ::xcrate::S;
-    //~^ ERROR failed to resolve. Could not find `xcrate` in `{{root}}`
+    //~^ ERROR failed to resolve: could not find `xcrate` in `{{root}}`
 }
diff --git a/src/test/ui/rfc-2126-extern-absolute-paths/non-existent-2.stderr b/src/test/ui/rfc-2126-extern-absolute-paths/non-existent-2.stderr
index b46576b0143..30e5b0ad1df 100644
--- a/src/test/ui/rfc-2126-extern-absolute-paths/non-existent-2.stderr
+++ b/src/test/ui/rfc-2126-extern-absolute-paths/non-existent-2.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve. Could not find `xcrate` in `{{root}}`
+error[E0433]: failed to resolve: could not find `xcrate` in `{{root}}`
   --> $DIR/non-existent-2.rs:14:15
    |
 LL |     let s = ::xcrate::S;
-   |               ^^^^^^ Could not find `xcrate` in `{{root}}`
+   |               ^^^^^^ could not find `xcrate` in `{{root}}`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/rfc-2126-extern-absolute-paths/not-whitelisted.rs b/src/test/ui/rfc-2126-extern-absolute-paths/not-whitelisted.rs
index f95961d2a9b..bfe7e4da845 100644
--- a/src/test/ui/rfc-2126-extern-absolute-paths/not-whitelisted.rs
+++ b/src/test/ui/rfc-2126-extern-absolute-paths/not-whitelisted.rs
@@ -10,10 +10,12 @@
 
 // edition:2018
 
+#![feature(uniform_paths)]
+
 // Tests that arbitrary crates (other than `core`, `std` and `meta`)
 // aren't allowed without `--extern`, even if they're in the sysroot.
 use alloc; //~ ERROR unresolved import `alloc`
-use test; //~ ERROR unresolved import `test`
-use proc_macro; //~ ERROR unresolved import `proc_macro`
+use test; //~ ERROR cannot import a built-in macro
+use proc_macro; // OK, imports the built-in `proc_macro` attribute, but not the `proc_macro` crate.
 
 fn main() {}
diff --git a/src/test/ui/rfc-2126-extern-absolute-paths/not-whitelisted.stderr b/src/test/ui/rfc-2126-extern-absolute-paths/not-whitelisted.stderr
index 0865bd6bea5..06c11b894dd 100644
--- a/src/test/ui/rfc-2126-extern-absolute-paths/not-whitelisted.stderr
+++ b/src/test/ui/rfc-2126-extern-absolute-paths/not-whitelisted.stderr
@@ -1,21 +1,15 @@
-error[E0432]: unresolved import `alloc`
-  --> $DIR/not-whitelisted.rs:15:5
-   |
-LL | use alloc; //~ ERROR unresolved import `alloc`
-   |     ^^^^^ no `alloc` external crate
-
-error[E0432]: unresolved import `test`
-  --> $DIR/not-whitelisted.rs:16:5
+error: cannot import a built-in macro
+  --> $DIR/not-whitelisted.rs:18:5
    |
-LL | use test; //~ ERROR unresolved import `test`
-   |     ^^^^ no `test` external crate
+LL | use test; //~ ERROR cannot import a built-in macro
+   |     ^^^^
 
-error[E0432]: unresolved import `proc_macro`
+error[E0432]: unresolved import `alloc`
   --> $DIR/not-whitelisted.rs:17:5
    |
-LL | use proc_macro; //~ ERROR unresolved import `proc_macro`
-   |     ^^^^^^^^^^ no `proc_macro` external crate
+LL | use alloc; //~ ERROR unresolved import `alloc`
+   |     ^^^^^ no `alloc` external crate
 
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0432`.
diff --git a/src/test/ui/rfc-2126-extern-in-paths/non-existent-1.stderr b/src/test/ui/rfc-2126-extern-in-paths/non-existent-1.stderr
index 55b8b625507..47ea4b8dfcb 100644
--- a/src/test/ui/rfc-2126-extern-in-paths/non-existent-1.stderr
+++ b/src/test/ui/rfc-2126-extern-in-paths/non-existent-1.stderr
@@ -2,7 +2,7 @@ error[E0432]: unresolved import `extern::xcrate`
   --> $DIR/non-existent-1.rs:13:13
    |
 LL | use extern::xcrate::S; //~ ERROR unresolved import `extern::xcrate`
-   |             ^^^^^^ Could not find `xcrate` in `extern`
+   |             ^^^^^^ could not find `xcrate` in `extern`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/rfc-2126-extern-in-paths/non-existent-2.rs b/src/test/ui/rfc-2126-extern-in-paths/non-existent-2.rs
index 128ecf41a30..8d7c3993c62 100644
--- a/src/test/ui/rfc-2126-extern-in-paths/non-existent-2.rs
+++ b/src/test/ui/rfc-2126-extern-in-paths/non-existent-2.rs
@@ -12,5 +12,5 @@
 
 fn main() {
     let s = extern::xcrate::S;
-    //~^ ERROR failed to resolve. Could not find `xcrate` in `extern`
+    //~^ ERROR failed to resolve: could not find `xcrate` in `extern`
 }
diff --git a/src/test/ui/rfc-2126-extern-in-paths/non-existent-2.stderr b/src/test/ui/rfc-2126-extern-in-paths/non-existent-2.stderr
index 7fbe50a9202..89630adb5a8 100644
--- a/src/test/ui/rfc-2126-extern-in-paths/non-existent-2.stderr
+++ b/src/test/ui/rfc-2126-extern-in-paths/non-existent-2.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve. Could not find `xcrate` in `extern`
+error[E0433]: failed to resolve: could not find `xcrate` in `extern`
   --> $DIR/non-existent-2.rs:14:21
    |
 LL |     let s = extern::xcrate::S;
-   |                     ^^^^^^ Could not find `xcrate` in `extern`
+   |                     ^^^^^^ could not find `xcrate` in `extern`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/rust-2018/future-proofing-locals.rs b/src/test/ui/rust-2018/future-proofing-locals.rs
new file mode 100644
index 00000000000..d2e6dbbb954
--- /dev/null
+++ b/src/test/ui/rust-2018/future-proofing-locals.rs
@@ -0,0 +1,49 @@
+// edition:2018
+
+#![feature(uniform_paths, underscore_imports)]
+
+mod T {
+    pub struct U;
+}
+mod x {
+    pub struct y;
+}
+
+fn type_param<T>() {
+    use T as _; //~ ERROR imports cannot refer to type parameters
+    use T::U; //~ ERROR imports cannot refer to type parameters
+    use T::*; //~ ERROR imports cannot refer to type parameters
+}
+
+fn self_import<T>() {
+    use T; // FIXME Should be an error, but future-proofing fails due to `T` being "self-shadowed"
+}
+
+fn let_binding() {
+    let x = 10;
+
+    use x as _; //~ ERROR imports cannot refer to local variables
+    use x::y; // OK
+    use x::*; // OK
+}
+
+fn param_binding(x: u8) {
+    use x; //~ ERROR imports cannot refer to local variables
+}
+
+fn match_binding() {
+    match 0 {
+        x => {
+            use x; //~ ERROR imports cannot refer to local variables
+        }
+    }
+}
+
+fn nested<T>() {
+    let x = 10;
+
+    use {T as _, x}; //~ ERROR imports cannot refer to type parameters
+                     //~| ERROR imports cannot refer to local variables
+}
+
+fn main() {}
diff --git a/src/test/ui/rust-2018/future-proofing-locals.stderr b/src/test/ui/rust-2018/future-proofing-locals.stderr
new file mode 100644
index 00000000000..68354b332a9
--- /dev/null
+++ b/src/test/ui/rust-2018/future-proofing-locals.stderr
@@ -0,0 +1,50 @@
+error: imports cannot refer to type parameters
+  --> $DIR/future-proofing-locals.rs:13:9
+   |
+LL |     use T as _; //~ ERROR imports cannot refer to type parameters
+   |         ^
+
+error: imports cannot refer to type parameters
+  --> $DIR/future-proofing-locals.rs:14:9
+   |
+LL |     use T::U; //~ ERROR imports cannot refer to type parameters
+   |         ^
+
+error: imports cannot refer to type parameters
+  --> $DIR/future-proofing-locals.rs:15:9
+   |
+LL |     use T::*; //~ ERROR imports cannot refer to type parameters
+   |         ^
+
+error: imports cannot refer to local variables
+  --> $DIR/future-proofing-locals.rs:25:9
+   |
+LL |     use x as _; //~ ERROR imports cannot refer to local variables
+   |         ^
+
+error: imports cannot refer to local variables
+  --> $DIR/future-proofing-locals.rs:31:9
+   |
+LL |     use x; //~ ERROR imports cannot refer to local variables
+   |         ^
+
+error: imports cannot refer to local variables
+  --> $DIR/future-proofing-locals.rs:37:17
+   |
+LL |             use x; //~ ERROR imports cannot refer to local variables
+   |                 ^
+
+error: imports cannot refer to type parameters
+  --> $DIR/future-proofing-locals.rs:45:10
+   |
+LL |     use {T as _, x}; //~ ERROR imports cannot refer to type parameters
+   |          ^
+
+error: imports cannot refer to local variables
+  --> $DIR/future-proofing-locals.rs:45:18
+   |
+LL |     use {T as _, x}; //~ ERROR imports cannot refer to type parameters
+   |                  ^
+
+error: aborting due to 8 previous errors
+
diff --git a/src/test/ui/rust-2018/issue-54006.stderr b/src/test/ui/rust-2018/issue-54006.stderr
index 268a16e5d2a..5f92574c23f 100644
--- a/src/test/ui/rust-2018/issue-54006.stderr
+++ b/src/test/ui/rust-2018/issue-54006.stderr
@@ -2,7 +2,7 @@ error[E0432]: unresolved import `alloc`
   --> $DIR/issue-54006.rs:16:5
    |
 LL | use alloc::vec;
-   |     ^^^^^ Did you mean `core::alloc`?
+   |     ^^^^^ did you mean `core::alloc`?
 
 error: cannot determine resolution for the macro `vec`
   --> $DIR/issue-54006.rs:20:18
diff --git a/src/test/ui/rust-2018/local-path-suggestions-2015.stderr b/src/test/ui/rust-2018/local-path-suggestions-2015.stderr
index d7580507ce4..741b2ca0826 100644
--- a/src/test/ui/rust-2018/local-path-suggestions-2015.stderr
+++ b/src/test/ui/rust-2018/local-path-suggestions-2015.stderr
@@ -2,7 +2,7 @@ error[E0432]: unresolved import `foobar`
   --> $DIR/local-path-suggestions-2015.rs:34:5
    |
 LL | use foobar::Baz;
-   |     ^^^^^^ Did you mean `aux_baz::foobar`?
+   |     ^^^^^^ did you mean `aux_baz::foobar`?
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/rust-2018/local-path-suggestions-2018.rs b/src/test/ui/rust-2018/local-path-suggestions-2018.rs
index 147dae401f6..0d4aefff931 100644
--- a/src/test/ui/rust-2018/local-path-suggestions-2018.rs
+++ b/src/test/ui/rust-2018/local-path-suggestions-2018.rs
@@ -12,12 +12,14 @@
 // compile-flags:--extern baz
 // edition:2018
 
+#![feature(uniform_paths)]
+
 mod foo {
     pub type Bar = u32;
 }
 
-mod baz {
-    use foo::Bar;
+mod bazz {
+    use foo::Bar; //~ ERROR unresolved import `foo`
 
     fn baz() {
         let x: Bar = 22;
@@ -26,6 +28,6 @@ mod baz {
 
 use foo::Bar;
 
-use foobar::Baz;
+use foobar::Baz; //~ ERROR unresolved import `foobar`
 
 fn main() { }
diff --git a/src/test/ui/rust-2018/local-path-suggestions-2018.stderr b/src/test/ui/rust-2018/local-path-suggestions-2018.stderr
index 2293f4b0017..a445a4c612b 100644
--- a/src/test/ui/rust-2018/local-path-suggestions-2018.stderr
+++ b/src/test/ui/rust-2018/local-path-suggestions-2018.stderr
@@ -1,23 +1,17 @@
 error[E0432]: unresolved import `foo`
-  --> $DIR/local-path-suggestions-2018.rs:20:9
+  --> $DIR/local-path-suggestions-2018.rs:22:9
    |
-LL |     use foo::Bar;
-   |         ^^^ Did you mean `crate::foo`?
+LL |     use foo::Bar; //~ ERROR unresolved import `foo`
+   |         ^^^ did you mean `crate::foo`?
    |
    = note: `use` statements changed in Rust 2018; read more at <https://doc.rust-lang.org/edition-guide/rust-2018/module-system/path-clarity.html>
 
-error[E0432]: unresolved import `foo`
-  --> $DIR/local-path-suggestions-2018.rs:27:5
-   |
-LL | use foo::Bar;
-   |     ^^^ Did you mean `self::foo`?
-
 error[E0432]: unresolved import `foobar`
-  --> $DIR/local-path-suggestions-2018.rs:29:5
+  --> $DIR/local-path-suggestions-2018.rs:31:5
    |
-LL | use foobar::Baz;
-   |     ^^^^^^ Did you mean `baz::foobar`?
+LL | use foobar::Baz; //~ ERROR unresolved import `foobar`
+   |     ^^^^^^ did you mean `baz::foobar`?
 
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0432`.
diff --git a/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-macros-nested.rs b/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-macros-nested.rs
index 590e83b0781..4819711115c 100644
--- a/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-macros-nested.rs
+++ b/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-macros-nested.rs
@@ -14,7 +14,7 @@
 
 mod foo {
     pub use std::io;
-    //~^ ERROR `std` import is ambiguous
+    //~^ ERROR `std` is ambiguous
 
     macro_rules! m {
         () => {
diff --git a/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-macros-nested.stderr b/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-macros-nested.stderr
index 948043cff76..204e0a7e141 100644
--- a/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-macros-nested.stderr
+++ b/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-macros-nested.stderr
@@ -1,16 +1,23 @@
-error: `std` import is ambiguous
+error[E0659]: `std` is ambiguous (name vs any other name during import resolution)
   --> $DIR/ambiguity-macros-nested.rs:16:13
    |
-LL |       pub use std::io;
-   |               ^^^ can refer to external crate `::std`
-...
+LL |     pub use std::io;
+   |             ^^^ ambiguous name
+   |
+   = note: `std` could refer to a built-in extern crate
+   = help: use `::std` to refer to this extern crate unambiguously
+note: `std` could also refer to the module defined here
+  --> $DIR/ambiguity-macros-nested.rs:21:13
+   |
 LL | /             mod std {
 LL | |                 pub struct io;
 LL | |             }
-   | |_____________- may refer to `self::std` in the future
-   |
-   = help: write `::std` or `self::std` explicitly instead
-   = note: in the future, `#![feature(uniform_paths)]` may become the default
+   | |_____________^
+...
+LL |       m!();
+   |       ----- in this macro invocation
+   = help: use `self::std` to refer to this module unambiguously
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0659`.
diff --git a/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-macros.rs b/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-macros.rs
index 861efba14f8..148320de556 100644
--- a/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-macros.rs
+++ b/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-macros.rs
@@ -13,7 +13,7 @@
 // This test is similar to `ambiguity.rs`, but with macros defining local items.
 
 use std::io;
-//~^ ERROR `std` import is ambiguous
+//~^ ERROR `std` is ambiguous
 
 macro_rules! m {
     () => {
diff --git a/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-macros.stderr b/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-macros.stderr
index 40cceea2440..ac8d3b9d0cb 100644
--- a/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-macros.stderr
+++ b/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-macros.stderr
@@ -1,16 +1,23 @@
-error: `std` import is ambiguous
+error[E0659]: `std` is ambiguous (name vs any other name during import resolution)
   --> $DIR/ambiguity-macros.rs:15:5
    |
-LL |   use std::io;
-   |       ^^^ can refer to external crate `::std`
-...
+LL | use std::io;
+   |     ^^^ ambiguous name
+   |
+   = note: `std` could refer to a built-in extern crate
+   = help: use `::std` to refer to this extern crate unambiguously
+note: `std` could also refer to the module defined here
+  --> $DIR/ambiguity-macros.rs:20:9
+   |
 LL | /         mod std {
 LL | |             pub struct io;
 LL | |         }
-   | |_________- may refer to `self::std` in the future
-   |
-   = help: write `::std` or `self::std` explicitly instead
-   = note: in the future, `#![feature(uniform_paths)]` may become the default
+   | |_________^
+...
+LL |   m!();
+   |   ----- in this macro invocation
+   = help: use `self::std` to refer to this module unambiguously
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0659`.
diff --git a/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-nested.rs b/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-nested.rs
index a69eb101917..2791d4580da 100644
--- a/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-nested.rs
+++ b/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-nested.rs
@@ -14,7 +14,7 @@
 
 mod foo {
     pub use std::io;
-    //~^ ERROR `std` import is ambiguous
+    //~^ ERROR `std` is ambiguous
 
     mod std {
         pub struct io;
diff --git a/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-nested.stderr b/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-nested.stderr
index 7538d3d2d91..7bcfc563d39 100644
--- a/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-nested.stderr
+++ b/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity-nested.stderr
@@ -1,16 +1,20 @@
-error: `std` import is ambiguous
+error[E0659]: `std` is ambiguous (name vs any other name during import resolution)
   --> $DIR/ambiguity-nested.rs:16:13
    |
-LL |       pub use std::io;
-   |               ^^^ can refer to external crate `::std`
-...
+LL |     pub use std::io;
+   |             ^^^ ambiguous name
+   |
+   = note: `std` could refer to a built-in extern crate
+   = help: use `::std` to refer to this extern crate unambiguously
+note: `std` could also refer to the module defined here
+  --> $DIR/ambiguity-nested.rs:19:5
+   |
 LL | /     mod std {
 LL | |         pub struct io;
 LL | |     }
-   | |_____- may refer to `self::std` in the future
-   |
-   = help: write `::std` or `self::std` explicitly instead
-   = note: in the future, `#![feature(uniform_paths)]` may become the default
+   | |_____^
+   = help: use `self::std` to refer to this module unambiguously
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0659`.
diff --git a/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity.rs b/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity.rs
index 500e9f6c63f..2bfbb6b2871 100644
--- a/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity.rs
+++ b/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity.rs
@@ -11,7 +11,7 @@
 // edition:2018
 
 use std::io;
-//~^ ERROR `std` import is ambiguous
+//~^ ERROR `std` is ambiguous
 
 mod std {
     pub struct io;
diff --git a/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity.stderr b/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity.stderr
index 7b64b8f0246..beeb74654e5 100644
--- a/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity.stderr
+++ b/src/test/ui/rust-2018/uniform-paths-forward-compat/ambiguity.stderr
@@ -1,16 +1,20 @@
-error: `std` import is ambiguous
+error[E0659]: `std` is ambiguous (name vs any other name during import resolution)
   --> $DIR/ambiguity.rs:13:5
    |
-LL |   use std::io;
-   |       ^^^ can refer to external crate `::std`
-...
+LL | use std::io;
+   |     ^^^ ambiguous name
+   |
+   = note: `std` could refer to a built-in extern crate
+   = help: use `::std` to refer to this extern crate unambiguously
+note: `std` could also refer to the module defined here
+  --> $DIR/ambiguity.rs:16:1
+   |
 LL | / mod std {
 LL | |     pub struct io;
 LL | | }
-   | |_- may refer to `self::std` in the future
-   |
-   = help: write `::std` or `self::std` explicitly instead
-   = note: in the future, `#![feature(uniform_paths)]` may become the default
+   | |_^
+   = help: use `self::std` to refer to this module unambiguously
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0659`.
diff --git a/src/test/ui/rust-2018/uniform-paths-forward-compat/block-scoped-shadow.rs b/src/test/ui/rust-2018/uniform-paths-forward-compat/block-scoped-shadow.rs
index ca488fec516..2853b4b3a5b 100644
--- a/src/test/ui/rust-2018/uniform-paths-forward-compat/block-scoped-shadow.rs
+++ b/src/test/ui/rust-2018/uniform-paths-forward-compat/block-scoped-shadow.rs
@@ -16,6 +16,6 @@ fn main() {
     fn std() {}
     enum std {}
     use std as foo;
-    //~^ ERROR `std` import is ambiguous
-    //~| ERROR `std` import is ambiguous
+    //~^ ERROR `std` is ambiguous
+    //~| ERROR `std` is ambiguous
 }
diff --git a/src/test/ui/rust-2018/uniform-paths-forward-compat/block-scoped-shadow.stderr b/src/test/ui/rust-2018/uniform-paths-forward-compat/block-scoped-shadow.stderr
index 27e0e883691..5d539e2d59f 100644
--- a/src/test/ui/rust-2018/uniform-paths-forward-compat/block-scoped-shadow.stderr
+++ b/src/test/ui/rust-2018/uniform-paths-forward-compat/block-scoped-shadow.stderr
@@ -1,31 +1,39 @@
-error: `std` import is ambiguous
+error[E0659]: `std` is ambiguous (name vs any other name during import resolution)
   --> $DIR/block-scoped-shadow.rs:18:9
    |
-LL | struct std;
-   | ----------- may refer to `self::std` in the future
-...
-LL |     enum std {}
-   |     ----------- shadowed by block-scoped `std`
 LL |     use std as foo;
-   |         ^^^ can refer to external crate `::std`
+   |         ^^^ ambiguous name
    |
-   = help: write `::std` or `self::std` explicitly instead
-   = note: in the future, `#![feature(uniform_paths)]` may become the default
+note: `std` could refer to the enum defined here
+  --> $DIR/block-scoped-shadow.rs:17:5
+   |
+LL |     enum std {}
+   |     ^^^^^^^^^^^
+note: `std` could also refer to the struct defined here
+  --> $DIR/block-scoped-shadow.rs:13:1
+   |
+LL | struct std;
+   | ^^^^^^^^^^^
+   = help: use `self::std` to refer to this struct unambiguously
 
-error: `std` import is ambiguous
+error[E0659]: `std` is ambiguous (name vs any other name during import resolution)
   --> $DIR/block-scoped-shadow.rs:18:9
    |
-LL | struct std;
-   | ----------- may refer to `self::std` in the future
-...
-LL |     fn std() {}
-   |     ----------- shadowed by block-scoped `std`
-LL |     enum std {}
 LL |     use std as foo;
-   |         ^^^
+   |         ^^^ ambiguous name
+   |
+note: `std` could refer to the function defined here
+  --> $DIR/block-scoped-shadow.rs:16:5
    |
-   = help: write `self::std` explicitly instead
-   = note: in the future, `#![feature(uniform_paths)]` may become the default
+LL |     fn std() {}
+   |     ^^^^^^^^^^^
+note: `std` could also refer to the unit struct defined here
+  --> $DIR/block-scoped-shadow.rs:13:1
+   |
+LL | struct std;
+   | ^^^^^^^^^^^
+   = help: use `self::std` to refer to this unit struct unambiguously
 
 error: aborting due to 2 previous errors
 
+For more information about this error, try `rustc --explain E0659`.
diff --git a/src/test/ui/rust-2018/uniform-paths-forward-compat/issue-54253.rs b/src/test/ui/rust-2018/uniform-paths-forward-compat/issue-54253.rs
index 1f19a05d7a7..ef2a1e3c70c 100644
--- a/src/test/ui/rust-2018/uniform-paths-forward-compat/issue-54253.rs
+++ b/src/test/ui/rust-2018/uniform-paths-forward-compat/issue-54253.rs
@@ -10,7 +10,7 @@
 
 // edition:2018
 
-// Dummy import to introduce `uniform_paths` canaries.
+// Dummy import that previously introduced uniform path canaries.
 use std;
 
 // fn version() -> &'static str {""}
diff --git a/src/test/ui/rust-2018/uniform-paths/ambiguity-macros-nested.rs b/src/test/ui/rust-2018/uniform-paths/ambiguity-macros-nested.rs
index e0992c90666..4819711115c 100644
--- a/src/test/ui/rust-2018/uniform-paths/ambiguity-macros-nested.rs
+++ b/src/test/ui/rust-2018/uniform-paths/ambiguity-macros-nested.rs
@@ -10,13 +10,11 @@
 
 // edition:2018
 
-#![feature(uniform_paths)]
-
 // This test is similar to `ambiguity-macros.rs`, but nested in a module.
 
 mod foo {
     pub use std::io;
-    //~^ ERROR `std` import is ambiguous
+    //~^ ERROR `std` is ambiguous
 
     macro_rules! m {
         () => {
diff --git a/src/test/ui/rust-2018/uniform-paths/ambiguity-macros-nested.stderr b/src/test/ui/rust-2018/uniform-paths/ambiguity-macros-nested.stderr
index 154ee412e72..204e0a7e141 100644
--- a/src/test/ui/rust-2018/uniform-paths/ambiguity-macros-nested.stderr
+++ b/src/test/ui/rust-2018/uniform-paths/ambiguity-macros-nested.stderr
@@ -1,16 +1,23 @@
-error: `std` import is ambiguous
-  --> $DIR/ambiguity-macros-nested.rs:18:13
+error[E0659]: `std` is ambiguous (name vs any other name during import resolution)
+  --> $DIR/ambiguity-macros-nested.rs:16:13
+   |
+LL |     pub use std::io;
+   |             ^^^ ambiguous name
+   |
+   = note: `std` could refer to a built-in extern crate
+   = help: use `::std` to refer to this extern crate unambiguously
+note: `std` could also refer to the module defined here
+  --> $DIR/ambiguity-macros-nested.rs:21:13
    |
-LL |       pub use std::io;
-   |               ^^^ can refer to external crate `::std`
-...
 LL | /             mod std {
 LL | |                 pub struct io;
 LL | |             }
-   | |_____________- can refer to `self::std`
-   |
-   = help: write `::std` or `self::std` explicitly instead
-   = note: relative `use` paths enabled by `#![feature(uniform_paths)]`
+   | |_____________^
+...
+LL |       m!();
+   |       ----- in this macro invocation
+   = help: use `self::std` to refer to this module unambiguously
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0659`.
diff --git a/src/test/ui/rust-2018/uniform-paths/ambiguity-macros.rs b/src/test/ui/rust-2018/uniform-paths/ambiguity-macros.rs
index 9439d92aa71..148320de556 100644
--- a/src/test/ui/rust-2018/uniform-paths/ambiguity-macros.rs
+++ b/src/test/ui/rust-2018/uniform-paths/ambiguity-macros.rs
@@ -10,12 +10,10 @@
 
 // edition:2018
 
-#![feature(uniform_paths)]
-
 // This test is similar to `ambiguity.rs`, but with macros defining local items.
 
 use std::io;
-//~^ ERROR `std` import is ambiguous
+//~^ ERROR `std` is ambiguous
 
 macro_rules! m {
     () => {
diff --git a/src/test/ui/rust-2018/uniform-paths/ambiguity-macros.stderr b/src/test/ui/rust-2018/uniform-paths/ambiguity-macros.stderr
index 3c0d5601f9c..ac8d3b9d0cb 100644
--- a/src/test/ui/rust-2018/uniform-paths/ambiguity-macros.stderr
+++ b/src/test/ui/rust-2018/uniform-paths/ambiguity-macros.stderr
@@ -1,16 +1,23 @@
-error: `std` import is ambiguous
-  --> $DIR/ambiguity-macros.rs:17:5
+error[E0659]: `std` is ambiguous (name vs any other name during import resolution)
+  --> $DIR/ambiguity-macros.rs:15:5
+   |
+LL | use std::io;
+   |     ^^^ ambiguous name
+   |
+   = note: `std` could refer to a built-in extern crate
+   = help: use `::std` to refer to this extern crate unambiguously
+note: `std` could also refer to the module defined here
+  --> $DIR/ambiguity-macros.rs:20:9
    |
-LL |   use std::io;
-   |       ^^^ can refer to external crate `::std`
-...
 LL | /         mod std {
 LL | |             pub struct io;
 LL | |         }
-   | |_________- can refer to `self::std`
-   |
-   = help: write `::std` or `self::std` explicitly instead
-   = note: relative `use` paths enabled by `#![feature(uniform_paths)]`
+   | |_________^
+...
+LL |   m!();
+   |   ----- in this macro invocation
+   = help: use `self::std` to refer to this module unambiguously
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0659`.
diff --git a/src/test/ui/rust-2018/uniform-paths/ambiguity-nested.rs b/src/test/ui/rust-2018/uniform-paths/ambiguity-nested.rs
index 1756acc6057..2791d4580da 100644
--- a/src/test/ui/rust-2018/uniform-paths/ambiguity-nested.rs
+++ b/src/test/ui/rust-2018/uniform-paths/ambiguity-nested.rs
@@ -10,13 +10,11 @@
 
 // edition:2018
 
-#![feature(uniform_paths)]
-
 // This test is similar to `ambiguity.rs`, but nested in a module.
 
 mod foo {
     pub use std::io;
-    //~^ ERROR `std` import is ambiguous
+    //~^ ERROR `std` is ambiguous
 
     mod std {
         pub struct io;
diff --git a/src/test/ui/rust-2018/uniform-paths/ambiguity-nested.stderr b/src/test/ui/rust-2018/uniform-paths/ambiguity-nested.stderr
index a607eeb0b43..7bcfc563d39 100644
--- a/src/test/ui/rust-2018/uniform-paths/ambiguity-nested.stderr
+++ b/src/test/ui/rust-2018/uniform-paths/ambiguity-nested.stderr
@@ -1,16 +1,20 @@
-error: `std` import is ambiguous
-  --> $DIR/ambiguity-nested.rs:18:13
+error[E0659]: `std` is ambiguous (name vs any other name during import resolution)
+  --> $DIR/ambiguity-nested.rs:16:13
+   |
+LL |     pub use std::io;
+   |             ^^^ ambiguous name
+   |
+   = note: `std` could refer to a built-in extern crate
+   = help: use `::std` to refer to this extern crate unambiguously
+note: `std` could also refer to the module defined here
+  --> $DIR/ambiguity-nested.rs:19:5
    |
-LL |       pub use std::io;
-   |               ^^^ can refer to external crate `::std`
-...
 LL | /     mod std {
 LL | |         pub struct io;
 LL | |     }
-   | |_____- can refer to `self::std`
-   |
-   = help: write `::std` or `self::std` explicitly instead
-   = note: relative `use` paths enabled by `#![feature(uniform_paths)]`
+   | |_____^
+   = help: use `self::std` to refer to this module unambiguously
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0659`.
diff --git a/src/test/ui/rust-2018/uniform-paths/ambiguity.rs b/src/test/ui/rust-2018/uniform-paths/ambiguity.rs
index 9ae3d79c22c..2bfbb6b2871 100644
--- a/src/test/ui/rust-2018/uniform-paths/ambiguity.rs
+++ b/src/test/ui/rust-2018/uniform-paths/ambiguity.rs
@@ -10,10 +10,8 @@
 
 // edition:2018
 
-#![feature(uniform_paths)]
-
 use std::io;
-//~^ ERROR `std` import is ambiguous
+//~^ ERROR `std` is ambiguous
 
 mod std {
     pub struct io;
diff --git a/src/test/ui/rust-2018/uniform-paths/ambiguity.stderr b/src/test/ui/rust-2018/uniform-paths/ambiguity.stderr
index c65db3072f4..beeb74654e5 100644
--- a/src/test/ui/rust-2018/uniform-paths/ambiguity.stderr
+++ b/src/test/ui/rust-2018/uniform-paths/ambiguity.stderr
@@ -1,16 +1,20 @@
-error: `std` import is ambiguous
-  --> $DIR/ambiguity.rs:15:5
+error[E0659]: `std` is ambiguous (name vs any other name during import resolution)
+  --> $DIR/ambiguity.rs:13:5
+   |
+LL | use std::io;
+   |     ^^^ ambiguous name
+   |
+   = note: `std` could refer to a built-in extern crate
+   = help: use `::std` to refer to this extern crate unambiguously
+note: `std` could also refer to the module defined here
+  --> $DIR/ambiguity.rs:16:1
    |
-LL |   use std::io;
-   |       ^^^ can refer to external crate `::std`
-...
 LL | / mod std {
 LL | |     pub struct io;
 LL | | }
-   | |_- can refer to `self::std`
-   |
-   = help: write `::std` or `self::std` explicitly instead
-   = note: relative `use` paths enabled by `#![feature(uniform_paths)]`
+   | |_^
+   = help: use `self::std` to refer to this module unambiguously
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0659`.
diff --git a/src/test/ui/rust-2018/uniform-paths/block-scoped-shadow-nested.rs b/src/test/ui/rust-2018/uniform-paths/block-scoped-shadow-nested.rs
new file mode 100644
index 00000000000..19be7dc9640
--- /dev/null
+++ b/src/test/ui/rust-2018/uniform-paths/block-scoped-shadow-nested.rs
@@ -0,0 +1,22 @@
+// edition:2018
+
+#![feature(uniform_paths)]
+
+mod my {
+    pub mod sub {
+        pub fn bar() {}
+    }
+}
+
+mod sub {
+    pub fn bar() {}
+}
+
+fn foo() {
+    use my::sub;
+    {
+        use sub::bar; //~ ERROR `sub` is ambiguous
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/rust-2018/uniform-paths/block-scoped-shadow-nested.stderr b/src/test/ui/rust-2018/uniform-paths/block-scoped-shadow-nested.stderr
new file mode 100644
index 00000000000..aa46947f93f
--- /dev/null
+++ b/src/test/ui/rust-2018/uniform-paths/block-scoped-shadow-nested.stderr
@@ -0,0 +1,23 @@
+error[E0659]: `sub` is ambiguous (name vs any other name during import resolution)
+  --> $DIR/block-scoped-shadow-nested.rs:18:13
+   |
+LL |         use sub::bar; //~ ERROR `sub` is ambiguous
+   |             ^^^ ambiguous name
+   |
+note: `sub` could refer to the module imported here
+  --> $DIR/block-scoped-shadow-nested.rs:16:9
+   |
+LL |     use my::sub;
+   |         ^^^^^^^
+note: `sub` could also refer to the module defined here
+  --> $DIR/block-scoped-shadow-nested.rs:11:1
+   |
+LL | / mod sub {
+LL | |     pub fn bar() {}
+LL | | }
+   | |_^
+   = help: use `self::sub` to refer to this module unambiguously
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0659`.
diff --git a/src/test/ui/rust-2018/uniform-paths/block-scoped-shadow.rs b/src/test/ui/rust-2018/uniform-paths/block-scoped-shadow.rs
index ee141d444b2..ec0479ce8f1 100644
--- a/src/test/ui/rust-2018/uniform-paths/block-scoped-shadow.rs
+++ b/src/test/ui/rust-2018/uniform-paths/block-scoped-shadow.rs
@@ -10,22 +10,20 @@
 
 // edition:2018
 
-#![feature(uniform_paths)]
-
-enum Foo { A, B }
+enum Foo {}
 
 struct std;
 
 fn main() {
-    enum Foo {}
+    enum Foo { A, B }
     use Foo::*;
-    //~^ ERROR `Foo` import is ambiguous
+    //~^ ERROR `Foo` is ambiguous
 
     let _ = (A, B);
 
     fn std() {}
     enum std {}
     use std as foo;
-    //~^ ERROR `std` import is ambiguous
-    //~| ERROR `std` import is ambiguous
+    //~^ ERROR `std` is ambiguous
+    //~| ERROR `std` is ambiguous
 }
diff --git a/src/test/ui/rust-2018/uniform-paths/block-scoped-shadow.stderr b/src/test/ui/rust-2018/uniform-paths/block-scoped-shadow.stderr
index 86d95f2ac45..010b9efad39 100644
--- a/src/test/ui/rust-2018/uniform-paths/block-scoped-shadow.stderr
+++ b/src/test/ui/rust-2018/uniform-paths/block-scoped-shadow.stderr
@@ -1,45 +1,57 @@
-error: `Foo` import is ambiguous
-  --> $DIR/block-scoped-shadow.rs:21:9
-   |
-LL | enum Foo { A, B }
-   | ----------------- can refer to `self::Foo`
-...
-LL |     enum Foo {}
-   |     ----------- shadowed by block-scoped `Foo`
+error[E0659]: `Foo` is ambiguous (name vs any other name during import resolution)
+  --> $DIR/block-scoped-shadow.rs:19:9
+   |
 LL |     use Foo::*;
-   |         ^^^
+   |         ^^^ ambiguous name
+   |
+note: `Foo` could refer to the enum defined here
+  --> $DIR/block-scoped-shadow.rs:18:5
    |
-   = help: write `self::Foo` explicitly instead
-   = note: relative `use` paths enabled by `#![feature(uniform_paths)]`
+LL |     enum Foo { A, B }
+   |     ^^^^^^^^^^^^^^^^^
+note: `Foo` could also refer to the enum defined here
+  --> $DIR/block-scoped-shadow.rs:13:1
+   |
+LL | enum Foo {}
+   | ^^^^^^^^^^^
+   = help: use `self::Foo` to refer to this enum unambiguously
 
-error: `std` import is ambiguous
-  --> $DIR/block-scoped-shadow.rs:28:9
+error[E0659]: `std` is ambiguous (name vs any other name during import resolution)
+  --> $DIR/block-scoped-shadow.rs:26:9
    |
-LL | struct std;
-   | ----------- can refer to `self::std`
-...
-LL |     enum std {}
-   |     ----------- shadowed by block-scoped `std`
 LL |     use std as foo;
-   |         ^^^ can refer to external crate `::std`
+   |         ^^^ ambiguous name
    |
-   = help: write `::std` or `self::std` explicitly instead
-   = note: relative `use` paths enabled by `#![feature(uniform_paths)]`
-
-error: `std` import is ambiguous
-  --> $DIR/block-scoped-shadow.rs:28:9
+note: `std` could refer to the enum defined here
+  --> $DIR/block-scoped-shadow.rs:25:5
    |
-LL | struct std;
-   | ----------- can refer to `self::std`
-...
-LL |     fn std() {}
-   |     ----------- shadowed by block-scoped `std`
 LL |     enum std {}
+   |     ^^^^^^^^^^^
+note: `std` could also refer to the struct defined here
+  --> $DIR/block-scoped-shadow.rs:15:1
+   |
+LL | struct std;
+   | ^^^^^^^^^^^
+   = help: use `self::std` to refer to this struct unambiguously
+
+error[E0659]: `std` is ambiguous (name vs any other name during import resolution)
+  --> $DIR/block-scoped-shadow.rs:26:9
+   |
 LL |     use std as foo;
-   |         ^^^
+   |         ^^^ ambiguous name
    |
-   = help: write `self::std` explicitly instead
-   = note: relative `use` paths enabled by `#![feature(uniform_paths)]`
+note: `std` could refer to the function defined here
+  --> $DIR/block-scoped-shadow.rs:24:5
+   |
+LL |     fn std() {}
+   |     ^^^^^^^^^^^
+note: `std` could also refer to the unit struct defined here
+  --> $DIR/block-scoped-shadow.rs:15:1
+   |
+LL | struct std;
+   | ^^^^^^^^^^^
+   = help: use `self::std` to refer to this unit struct unambiguously
 
 error: aborting due to 3 previous errors
 
+For more information about this error, try `rustc --explain E0659`.
diff --git a/src/test/ui/rust-2018/uniform-paths/deadlock.rs b/src/test/ui/rust-2018/uniform-paths/deadlock.rs
new file mode 100644
index 00000000000..3228d799083
--- /dev/null
+++ b/src/test/ui/rust-2018/uniform-paths/deadlock.rs
@@ -0,0 +1,7 @@
+// edition:2018
+// compile-flags:--extern foo --extern bar
+
+use foo::bar; //~ ERROR unresolved import
+use bar::foo;
+
+fn main() {}
diff --git a/src/test/ui/rust-2018/uniform-paths/deadlock.stderr b/src/test/ui/rust-2018/uniform-paths/deadlock.stderr
new file mode 100644
index 00000000000..8bbc8f33039
--- /dev/null
+++ b/src/test/ui/rust-2018/uniform-paths/deadlock.stderr
@@ -0,0 +1,9 @@
+error[E0432]: unresolved import
+  --> $DIR/deadlock.rs:4:5
+   |
+LL | use foo::bar; //~ ERROR unresolved import
+   |     ^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0432`.
diff --git a/src/test/ui/rust-2018/uniform-paths/fn-local-enum.rs b/src/test/ui/rust-2018/uniform-paths/fn-local-enum.rs
new file mode 100644
index 00000000000..a7bc625bbf0
--- /dev/null
+++ b/src/test/ui/rust-2018/uniform-paths/fn-local-enum.rs
@@ -0,0 +1,15 @@
+// compile-pass
+// edition:2018
+
+#![feature(uniform_paths)]
+
+fn main() {
+    enum E { A, B, C }
+
+    use E::*;
+    match A {
+        A => {}
+        B => {}
+        C => {}
+    }
+}
diff --git a/src/test/ui/rust-2018/uniform-paths/from-decl-macro.rs b/src/test/ui/rust-2018/uniform-paths/from-decl-macro.rs
new file mode 100644
index 00000000000..5c3c753f9a7
--- /dev/null
+++ b/src/test/ui/rust-2018/uniform-paths/from-decl-macro.rs
@@ -0,0 +1,12 @@
+// compile-pass
+// edition:2018
+
+#![feature(decl_macro)]
+
+macro check() {
+    ::std::vec::Vec::<u8>::new()
+}
+
+fn main() {
+    check!();
+}
diff --git a/src/test/ui/rust-2018/uniform-paths/issue-54253.rs b/src/test/ui/rust-2018/uniform-paths/issue-54253.rs
index 7ca5c9e9eae..ef2a1e3c70c 100644
--- a/src/test/ui/rust-2018/uniform-paths/issue-54253.rs
+++ b/src/test/ui/rust-2018/uniform-paths/issue-54253.rs
@@ -10,9 +10,7 @@
 
 // edition:2018
 
-#![feature(uniform_paths)]
-
-// Dummy import to introduce `uniform_paths` canaries.
+// Dummy import that previously introduced uniform path canaries.
 use std;
 
 // fn version() -> &'static str {""}
diff --git a/src/test/ui/rust-2018/uniform-paths/issue-54253.stderr b/src/test/ui/rust-2018/uniform-paths/issue-54253.stderr
index 0016e21ef4d..6dcc451c60a 100644
--- a/src/test/ui/rust-2018/uniform-paths/issue-54253.stderr
+++ b/src/test/ui/rust-2018/uniform-paths/issue-54253.stderr
@@ -1,5 +1,5 @@
 error[E0432]: unresolved import `crate::version`
-  --> $DIR/issue-54253.rs:22:9
+  --> $DIR/issue-54253.rs:20:9
    |
 LL |     use crate::version; //~ ERROR unresolved import `crate::version`
    |         ^^^^^^^^^^^^^^ no `version` in the root
diff --git a/src/test/ui/rust-2018/uniform-paths/issue-54390.rs b/src/test/ui/rust-2018/uniform-paths/issue-54390.rs
new file mode 100644
index 00000000000..536cc25e35a
--- /dev/null
+++ b/src/test/ui/rust-2018/uniform-paths/issue-54390.rs
@@ -0,0 +1,11 @@
+// edition:2018
+
+#![deny(unused)]
+
+use std::fmt;
+
+// No "unresolved import" + "unused import" combination here.
+use fmt::Write; //~ ERROR imports can only refer to extern crate names
+                //~| ERROR unused import: `fmt::Write`
+
+fn main() {}
diff --git a/src/test/ui/rust-2018/uniform-paths/issue-54390.stderr b/src/test/ui/rust-2018/uniform-paths/issue-54390.stderr
new file mode 100644
index 00000000000..8f86698c9c1
--- /dev/null
+++ b/src/test/ui/rust-2018/uniform-paths/issue-54390.stderr
@@ -0,0 +1,32 @@
+error[E0658]: imports can only refer to extern crate names passed with `--extern` on stable channel (see issue #53130)
+  --> $DIR/issue-54390.rs:8:5
+   |
+LL | use std::fmt;
+   |     -------- not an extern crate passed with `--extern`
+...
+LL | use fmt::Write; //~ ERROR imports can only refer to extern crate names
+   |     ^^^
+   |
+   = help: add #![feature(uniform_paths)] to the crate attributes to enable
+note: this import refers to the module imported here
+  --> $DIR/issue-54390.rs:5:5
+   |
+LL | use std::fmt;
+   |     ^^^^^^^^
+
+error: unused import: `fmt::Write`
+  --> $DIR/issue-54390.rs:8:5
+   |
+LL | use fmt::Write; //~ ERROR imports can only refer to extern crate names
+   |     ^^^^^^^^^^
+   |
+note: lint level defined here
+  --> $DIR/issue-54390.rs:3:9
+   |
+LL | #![deny(unused)]
+   |         ^^^^^^
+   = note: #[deny(unused_imports)] implied by #[deny(unused)]
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/rust-2018/uniform-paths/macro-rules.rs b/src/test/ui/rust-2018/uniform-paths/macro-rules.rs
new file mode 100644
index 00000000000..e8098a46790
--- /dev/null
+++ b/src/test/ui/rust-2018/uniform-paths/macro-rules.rs
@@ -0,0 +1,44 @@
+// edition:2018
+
+// For the time being `macro_rules` items are treated as *very* private...
+
+#![feature(underscore_imports, decl_macro, uniform_paths)]
+
+mod m1 {
+    macro_rules! legacy_macro { () => () }
+
+    // ... so they can't be imported by themselves, ...
+    use legacy_macro as _; //~ ERROR `legacy_macro` is private, and cannot be re-exported
+}
+
+mod m2 {
+    macro_rules! legacy_macro { () => () }
+
+    type legacy_macro = u8;
+
+    // ... but don't prevent names from other namespaces from being imported, ...
+    use legacy_macro as _; // OK
+}
+
+mod m3 {
+    macro legacy_macro() {}
+
+    fn f() {
+        macro_rules! legacy_macro { () => () }
+
+        // ... but still create ambiguities with other names in the same namespace.
+        use legacy_macro as _; //~ ERROR `legacy_macro` is ambiguous
+                               //~| ERROR `legacy_macro` is private, and cannot be re-exported
+    }
+}
+
+mod exported {
+    // Exported macros are treated as private as well,
+    // some better rules need to be figured out later.
+    #[macro_export]
+    macro_rules! legacy_macro { () => () }
+
+    use legacy_macro as _; //~ ERROR `legacy_macro` is private, and cannot be re-exported
+}
+
+fn main() {}
diff --git a/src/test/ui/rust-2018/uniform-paths/macro-rules.stderr b/src/test/ui/rust-2018/uniform-paths/macro-rules.stderr
new file mode 100644
index 00000000000..d7bb233dfe9
--- /dev/null
+++ b/src/test/ui/rust-2018/uniform-paths/macro-rules.stderr
@@ -0,0 +1,58 @@
+error[E0364]: `legacy_macro` is private, and cannot be re-exported
+  --> $DIR/macro-rules.rs:11:9
+   |
+LL |     use legacy_macro as _; //~ ERROR `legacy_macro` is private, and cannot be re-exported
+   |         ^^^^^^^^^^^^^^^^^
+   |
+note: consider marking `legacy_macro` as `pub` in the imported module
+  --> $DIR/macro-rules.rs:11:9
+   |
+LL |     use legacy_macro as _; //~ ERROR `legacy_macro` is private, and cannot be re-exported
+   |         ^^^^^^^^^^^^^^^^^
+
+error[E0364]: `legacy_macro` is private, and cannot be re-exported
+  --> $DIR/macro-rules.rs:30:13
+   |
+LL |         use legacy_macro as _; //~ ERROR `legacy_macro` is ambiguous
+   |             ^^^^^^^^^^^^^^^^^
+   |
+note: consider marking `legacy_macro` as `pub` in the imported module
+  --> $DIR/macro-rules.rs:30:13
+   |
+LL |         use legacy_macro as _; //~ ERROR `legacy_macro` is ambiguous
+   |             ^^^^^^^^^^^^^^^^^
+
+error[E0364]: `legacy_macro` is private, and cannot be re-exported
+  --> $DIR/macro-rules.rs:41:9
+   |
+LL |     use legacy_macro as _; //~ ERROR `legacy_macro` is private, and cannot be re-exported
+   |         ^^^^^^^^^^^^^^^^^
+   |
+note: consider marking `legacy_macro` as `pub` in the imported module
+  --> $DIR/macro-rules.rs:41:9
+   |
+LL |     use legacy_macro as _; //~ ERROR `legacy_macro` is private, and cannot be re-exported
+   |         ^^^^^^^^^^^^^^^^^
+
+error[E0659]: `legacy_macro` is ambiguous (name vs any other name during import resolution)
+  --> $DIR/macro-rules.rs:30:13
+   |
+LL |         use legacy_macro as _; //~ ERROR `legacy_macro` is ambiguous
+   |             ^^^^^^^^^^^^ ambiguous name
+   |
+note: `legacy_macro` could refer to the macro defined here
+  --> $DIR/macro-rules.rs:27:9
+   |
+LL |         macro_rules! legacy_macro { () => () }
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+note: `legacy_macro` could also refer to the macro defined here
+  --> $DIR/macro-rules.rs:24:5
+   |
+LL |     macro legacy_macro() {}
+   |     ^^^^^^^^^^^^^^^^^^^^^^^
+   = help: use `self::legacy_macro` to refer to this macro unambiguously
+
+error: aborting due to 4 previous errors
+
+Some errors occurred: E0364, E0659.
+For more information about an error, try `rustc --explain E0364`.
diff --git a/src/test/ui/rust-2018/uniform-paths/prelude-fail.rs b/src/test/ui/rust-2018/uniform-paths/prelude-fail.rs
new file mode 100644
index 00000000000..c5bd50f2f56
--- /dev/null
+++ b/src/test/ui/rust-2018/uniform-paths/prelude-fail.rs
@@ -0,0 +1,13 @@
+// edition:2018
+
+#![feature(uniform_paths)]
+
+// Built-in macro
+use env as env_imported; //~ ERROR cannot import a built-in macro
+
+// Tool attribute
+use rustfmt::skip as imported_rustfmt_skip; //~ ERROR unresolved import `rustfmt`
+
+fn main() {
+    env_imported!("PATH");
+}
diff --git a/src/test/ui/rust-2018/uniform-paths/prelude-fail.stderr b/src/test/ui/rust-2018/uniform-paths/prelude-fail.stderr
new file mode 100644
index 00000000000..794d986b82e
--- /dev/null
+++ b/src/test/ui/rust-2018/uniform-paths/prelude-fail.stderr
@@ -0,0 +1,15 @@
+error: cannot import a built-in macro
+  --> $DIR/prelude-fail.rs:6:5
+   |
+LL | use env as env_imported; //~ ERROR cannot import a built-in macro
+   |     ^^^^^^^^^^^^^^^^^^^
+
+error[E0432]: unresolved import `rustfmt`
+  --> $DIR/prelude-fail.rs:9:5
+   |
+LL | use rustfmt::skip as imported_rustfmt_skip; //~ ERROR unresolved import `rustfmt`
+   |     ^^^^^^^ not a module `rustfmt`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0432`.
diff --git a/src/test/ui/rust-2018/uniform-paths/prelude.rs b/src/test/ui/rust-2018/uniform-paths/prelude.rs
new file mode 100644
index 00000000000..5aab5fc3a40
--- /dev/null
+++ b/src/test/ui/rust-2018/uniform-paths/prelude.rs
@@ -0,0 +1,28 @@
+// compile-pass
+// edition:2018
+
+#![feature(uniform_paths)]
+
+// Macro imported with `#[macro_use] extern crate`
+use vec as imported_vec;
+
+// Built-in attribute
+use inline as imported_inline;
+
+// Tool module
+use rustfmt as imported_rustfmt;
+
+// Standard library prelude
+use Vec as ImportedVec;
+
+// Built-in type
+use u8 as imported_u8;
+
+type A = imported_u8;
+
+#[imported_inline]
+#[imported_rustfmt::skip]
+fn main() {
+    imported_vec![0];
+    ImportedVec::<u8>::new();
+}
diff --git a/src/test/ui/rust-2018/uniform-paths/redundant.rs b/src/test/ui/rust-2018/uniform-paths/redundant.rs
index 745ac18e059..05048cfd451 100644
--- a/src/test/ui/rust-2018/uniform-paths/redundant.rs
+++ b/src/test/ui/rust-2018/uniform-paths/redundant.rs
@@ -11,8 +11,6 @@
 // run-pass
 // edition:2018
 
-#![feature(uniform_paths)]
-
 use std;
 use std::io;
 
diff --git a/src/test/ui/span/macro-ty-params.stderr b/src/test/ui/span/macro-ty-params.stderr
index 3988dec88d5..8a40556a6cd 100644
--- a/src/test/ui/span/macro-ty-params.stderr
+++ b/src/test/ui/span/macro-ty-params.stderr
@@ -5,6 +5,12 @@ LL |     m!(MyTrait<>); //~ ERROR generic arguments in macro path
    |        ^^^^^^^^^
 
 error: generic arguments in macro path
+  --> $DIR/macro-ty-params.rs:20:15
+   |
+LL |     m!(MyTrait<>); //~ ERROR generic arguments in macro path
+   |               ^^
+
+error: generic arguments in macro path
   --> $DIR/macro-ty-params.rs:18:8
    |
 LL |     foo::<T>!(); //~ ERROR generic arguments in macro path
@@ -16,11 +22,5 @@ error: generic arguments in macro path
 LL |     foo::<>!(); //~ ERROR generic arguments in macro path
    |        ^^^^
 
-error: generic arguments in macro path
-  --> $DIR/macro-ty-params.rs:20:15
-   |
-LL |     m!(MyTrait<>); //~ ERROR generic arguments in macro path
-   |               ^^
-
 error: aborting due to 4 previous errors
 
diff --git a/src/test/ui/span/non-existing-module-import.stderr b/src/test/ui/span/non-existing-module-import.stderr
index 5518b42ac65..1f001530f36 100644
--- a/src/test/ui/span/non-existing-module-import.stderr
+++ b/src/test/ui/span/non-existing-module-import.stderr
@@ -2,7 +2,7 @@ error[E0432]: unresolved import `std::bar`
   --> $DIR/non-existing-module-import.rs:11:10
    |
 LL | use std::bar::{foo1, foo2}; //~ ERROR unresolved import
-   |          ^^^ Could not find `bar` in `std`
+   |          ^^^ could not find `bar` in `std`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/static/static-mut-not-pat.stderr b/src/test/ui/static/static-mut-not-pat.stderr
index 123cf7b3ac6..96dc06ee524 100644
--- a/src/test/ui/static/static-mut-not-pat.stderr
+++ b/src/test/ui/static/static-mut-not-pat.stderr
@@ -2,7 +2,7 @@ error[E0530]: match bindings cannot shadow statics
   --> $DIR/static-mut-not-pat.rs:23:9
    |
 LL | static mut a: isize = 3;
-   | ------------------------ a static `a` is defined here
+   | ------------------------ the static `a` is defined here
 ...
 LL |         a => {} //~ ERROR match bindings cannot shadow statics
    |         ^ cannot be named the same as a static
@@ -11,7 +11,7 @@ error[E0530]: match bindings cannot shadow statics
   --> $DIR/static-mut-not-pat.rs:46:9
    |
 LL | static mut STATIC_MUT_FOO: Foo = Foo { bar: Some(Direction::West), baz: NEW_FALSE };
-   | ------------------------------------------------------------------------------------ a static `STATIC_MUT_FOO` is defined here
+   | ------------------------------------------------------------------------------------ the static `STATIC_MUT_FOO` is defined here
 ...
 LL |         STATIC_MUT_FOO => (),
    |         ^^^^^^^^^^^^^^ cannot be named the same as a static
diff --git a/src/test/ui/super-at-top-level.rs b/src/test/ui/super-at-top-level.rs
index c607711c44f..96d099c7655 100644
--- a/src/test/ui/super-at-top-level.rs
+++ b/src/test/ui/super-at-top-level.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use super::f; //~ ERROR There are too many initial `super`s
+use super::f; //~ ERROR there are too many initial `super`s
 
 fn main() {
 }
diff --git a/src/test/ui/super-at-top-level.stderr b/src/test/ui/super-at-top-level.stderr
index b4af73055a0..8402daad19e 100644
--- a/src/test/ui/super-at-top-level.stderr
+++ b/src/test/ui/super-at-top-level.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve. There are too many initial `super`s.
+error[E0433]: failed to resolve: there are too many initial `super`s.
   --> $DIR/super-at-top-level.rs:11:5
    |
-LL | use super::f; //~ ERROR There are too many initial `super`s
-   |     ^^^^^ There are too many initial `super`s.
+LL | use super::f; //~ ERROR there are too many initial `super`s
+   |     ^^^^^ there are too many initial `super`s.
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/tool-attributes/tool-attributes-shadowing.rs b/src/test/ui/tool-attributes/tool-attributes-shadowing.rs
index b6a24ccf748..11e28857afe 100644
--- a/src/test/ui/tool-attributes/tool-attributes-shadowing.rs
+++ b/src/test/ui/tool-attributes/tool-attributes-shadowing.rs
@@ -10,5 +10,5 @@
 
 mod rustfmt {}
 
-#[rustfmt::skip] //~ ERROR failed to resolve. Could not find `skip` in `rustfmt`
+#[rustfmt::skip] //~ ERROR failed to resolve: could not find `skip` in `rustfmt`
 fn main() {}
diff --git a/src/test/ui/tool-attributes/tool-attributes-shadowing.stderr b/src/test/ui/tool-attributes/tool-attributes-shadowing.stderr
index d593350f123..0839e363c36 100644
--- a/src/test/ui/tool-attributes/tool-attributes-shadowing.stderr
+++ b/src/test/ui/tool-attributes/tool-attributes-shadowing.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve. Could not find `skip` in `rustfmt`
+error[E0433]: failed to resolve: could not find `skip` in `rustfmt`
   --> $DIR/tool-attributes-shadowing.rs:13:12
    |
-LL | #[rustfmt::skip] //~ ERROR failed to resolve. Could not find `skip` in `rustfmt`
-   |            ^^^^ Could not find `skip` in `rustfmt`
+LL | #[rustfmt::skip] //~ ERROR failed to resolve: could not find `skip` in `rustfmt`
+   |            ^^^^ could not find `skip` in `rustfmt`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/type/type-path-err-node-types.stderr b/src/test/ui/type/type-path-err-node-types.stderr
index c28b30b5456..df7d442239b 100644
--- a/src/test/ui/type/type-path-err-node-types.stderr
+++ b/src/test/ui/type/type-path-err-node-types.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve. Use of undeclared type or module `NonExistent`
+error[E0433]: failed to resolve: use of undeclared type or module `NonExistent`
   --> $DIR/type-path-err-node-types.rs:25:5
    |
 LL |     NonExistent::Assoc::<u8>; //~ ERROR undeclared type or module `NonExistent`
-   |     ^^^^^^^^^^^ Use of undeclared type or module `NonExistent`
+   |     ^^^^^^^^^^^ use of undeclared type or module `NonExistent`
 
 error[E0412]: cannot find type `Nonexistent` in this scope
   --> $DIR/type-path-err-node-types.rs:17:12
diff --git a/src/test/ui/ufcs/ufcs-partially-resolved.rs b/src/test/ui/ufcs/ufcs-partially-resolved.rs
index f7120ddb114..db10197ded1 100644
--- a/src/test/ui/ufcs/ufcs-partially-resolved.rs
+++ b/src/test/ui/ufcs/ufcs-partially-resolved.rs
@@ -55,9 +55,9 @@ fn main() {
     <u8 as E::N>::NN; //~ ERROR cannot find method or associated constant `NN` in `E::N`
     <u8 as A::N>::NN; //~ ERROR cannot find method or associated constant `NN` in `A::N`
     let _: <u8 as Tr::Y>::NN; //~ ERROR cannot find associated type `NN` in `Tr::Y`
-    let _: <u8 as E::Y>::NN; //~ ERROR failed to resolve. Not a module `Y`
+    let _: <u8 as E::Y>::NN; //~ ERROR failed to resolve: not a module `Y`
     <u8 as Tr::Y>::NN; //~ ERROR cannot find method or associated constant `NN` in `Tr::Y`
-    <u8 as E::Y>::NN; //~ ERROR failed to resolve. Not a module `Y`
+    <u8 as E::Y>::NN; //~ ERROR failed to resolve: not a module `Y`
 
     let _: <u8 as Dr>::Z; //~ ERROR expected associated type, found method `Dr::Z`
     <u8 as Dr>::X; //~ ERROR expected method or associated constant, found associated type `Dr::X`
diff --git a/src/test/ui/ufcs/ufcs-partially-resolved.stderr b/src/test/ui/ufcs/ufcs-partially-resolved.stderr
index 77d887f1d68..cb571be661d 100644
--- a/src/test/ui/ufcs/ufcs-partially-resolved.stderr
+++ b/src/test/ui/ufcs/ufcs-partially-resolved.stderr
@@ -1,14 +1,14 @@
-error[E0433]: failed to resolve. Not a module `Y`
+error[E0433]: failed to resolve: not a module `Y`
   --> $DIR/ufcs-partially-resolved.rs:58:22
    |
-LL |     let _: <u8 as E::Y>::NN; //~ ERROR failed to resolve. Not a module `Y`
-   |                      ^ Not a module `Y`
+LL |     let _: <u8 as E::Y>::NN; //~ ERROR failed to resolve: not a module `Y`
+   |                      ^ not a module `Y`
 
-error[E0433]: failed to resolve. Not a module `Y`
+error[E0433]: failed to resolve: not a module `Y`
   --> $DIR/ufcs-partially-resolved.rs:60:15
    |
-LL |     <u8 as E::Y>::NN; //~ ERROR failed to resolve. Not a module `Y`
-   |               ^ Not a module `Y`
+LL |     <u8 as E::Y>::NN; //~ ERROR failed to resolve: not a module `Y`
+   |               ^ not a module `Y`
 
 error[E0576]: cannot find associated type `N` in trait `Tr`
   --> $DIR/ufcs-partially-resolved.rs:29:24
diff --git a/src/test/ui/unknown-tool-name.rs b/src/test/ui/unknown-tool-name.rs
index cd2aeb7494a..8d7a6225529 100644
--- a/src/test/ui/unknown-tool-name.rs
+++ b/src/test/ui/unknown-tool-name.rs
@@ -8,5 +8,5 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#[foo::bar] //~ ERROR failed to resolve. Use of undeclared type or module `foo`
+#[foo::bar] //~ ERROR failed to resolve: use of undeclared type or module `foo`
 fn main() {}
diff --git a/src/test/ui/unknown-tool-name.stderr b/src/test/ui/unknown-tool-name.stderr
index 8381c6de83a..55096614fcd 100644
--- a/src/test/ui/unknown-tool-name.stderr
+++ b/src/test/ui/unknown-tool-name.stderr
@@ -1,8 +1,8 @@
-error[E0433]: failed to resolve. Use of undeclared type or module `foo`
+error[E0433]: failed to resolve: use of undeclared type or module `foo`
   --> $DIR/unknown-tool-name.rs:11:3
    |
-LL | #[foo::bar] //~ ERROR failed to resolve. Use of undeclared type or module `foo`
-   |   ^^^ Use of undeclared type or module `foo`
+LL | #[foo::bar] //~ ERROR failed to resolve: use of undeclared type or module `foo`
+   |   ^^^ use of undeclared type or module `foo`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/unresolved/unresolved-import.rs b/src/test/ui/unresolved/unresolved-import.rs
index efa74946476..4592289beeb 100644
--- a/src/test/ui/unresolved/unresolved-import.rs
+++ b/src/test/ui/unresolved/unresolved-import.rs
@@ -11,7 +11,7 @@
 // ignore-tidy-linelength
 
 use foo::bar; //~ ERROR unresolved import `foo` [E0432]
-              //~^ Maybe a missing `extern crate foo;`?
+              //~^ maybe a missing `extern crate foo;`?
 
 use bar::Baz as x; //~ ERROR unresolved import `bar::Baz` [E0432]
                    //~^ no `Baz` in `bar`. Did you mean to use `Bar`?
@@ -42,7 +42,7 @@ mod m {
     }
 
     use MyEnum::*; //~ ERROR unresolved import `MyEnum` [E0432]
-                   //~^ Did you mean `self::MyEnum`?
+                   //~^ did you mean `self::MyEnum`?
 }
 
 mod items {
@@ -51,7 +51,7 @@ mod items {
     }
 
     use Enum::*; //~ ERROR unresolved import `Enum` [E0432]
-                 //~^ Did you mean `self::Enum`?
+                 //~^ did you mean `self::Enum`?
 
     fn item() {}
 }
diff --git a/src/test/ui/unresolved/unresolved-import.stderr b/src/test/ui/unresolved/unresolved-import.stderr
index 9bcebb0011a..7e98a41af10 100644
--- a/src/test/ui/unresolved/unresolved-import.stderr
+++ b/src/test/ui/unresolved/unresolved-import.stderr
@@ -2,7 +2,7 @@ error[E0432]: unresolved import `foo`
   --> $DIR/unresolved-import.rs:13:5
    |
 LL | use foo::bar; //~ ERROR unresolved import `foo` [E0432]
-   |     ^^^ Maybe a missing `extern crate foo;`?
+   |     ^^^ maybe a missing `extern crate foo;`?
 
 error[E0432]: unresolved import `bar::Baz`
   --> $DIR/unresolved-import.rs:16:5
@@ -26,13 +26,13 @@ error[E0432]: unresolved import `MyEnum`
   --> $DIR/unresolved-import.rs:44:9
    |
 LL |     use MyEnum::*; //~ ERROR unresolved import `MyEnum` [E0432]
-   |         ^^^^^^ Did you mean `self::MyEnum`?
+   |         ^^^^^^ did you mean `self::MyEnum`?
 
 error[E0432]: unresolved import `Enum`
   --> $DIR/unresolved-import.rs:53:9
    |
 LL |     use Enum::*; //~ ERROR unresolved import `Enum` [E0432]
-   |         ^^^^ Did you mean `self::Enum`?
+   |         ^^^^ did you mean `self::Enum`?
 
 error: aborting due to 6 previous errors
 
diff --git a/src/test/ui/use/use-from-trait-xc.stderr b/src/test/ui/use/use-from-trait-xc.stderr
index f8e5e18097b..6c643dff796 100644
--- a/src/test/ui/use/use-from-trait-xc.stderr
+++ b/src/test/ui/use/use-from-trait-xc.stderr
@@ -20,19 +20,19 @@ error[E0432]: unresolved import `use_from_trait_xc::Foo`
   --> $DIR/use-from-trait-xc.rs:24:24
    |
 LL | use use_from_trait_xc::Foo::new; //~ ERROR struct `Foo` is private
-   |                        ^^^ Not a module `Foo`
+   |                        ^^^ not a module `Foo`
 
 error[E0432]: unresolved import `use_from_trait_xc::Foo`
   --> $DIR/use-from-trait-xc.rs:27:24
    |
 LL | use use_from_trait_xc::Foo::C; //~ ERROR struct `Foo` is private
-   |                        ^^^ Not a module `Foo`
+   |                        ^^^ not a module `Foo`
 
 error[E0432]: unresolved import `use_from_trait_xc::Bar`
   --> $DIR/use-from-trait-xc.rs:30:24
    |
 LL | use use_from_trait_xc::Bar::new as bnew;
-   |                        ^^^ Not a module `Bar`
+   |                        ^^^ not a module `Bar`
 
 error[E0432]: unresolved import `use_from_trait_xc::Baz::new`
   --> $DIR/use-from-trait-xc.rs:33:5
diff --git a/src/test/ui/use/use-from-trait.rs b/src/test/ui/use/use-from-trait.rs
index 29db949acd0..afa76320582 100644
--- a/src/test/ui/use/use-from-trait.rs
+++ b/src/test/ui/use/use-from-trait.rs
@@ -18,11 +18,11 @@ use Trait::C;
 
 use Foo::new;
 //~^ ERROR unresolved import `Foo` [E0432]
-//~| Not a module `Foo`
+//~| not a module `Foo`
 
 use Foo::C2;
 //~^ ERROR unresolved import `Foo` [E0432]
-//~| Not a module `Foo`
+//~| not a module `Foo`
 
 pub trait Trait {
     fn foo();
diff --git a/src/test/ui/use/use-from-trait.stderr b/src/test/ui/use/use-from-trait.stderr
index b43a32988ca..cb0fd94fa6e 100644
--- a/src/test/ui/use/use-from-trait.stderr
+++ b/src/test/ui/use/use-from-trait.stderr
@@ -20,13 +20,13 @@ error[E0432]: unresolved import `Foo`
   --> $DIR/use-from-trait.rs:19:5
    |
 LL | use Foo::new;
-   |     ^^^ Not a module `Foo`
+   |     ^^^ not a module `Foo`
 
 error[E0432]: unresolved import `Foo`
   --> $DIR/use-from-trait.rs:23:5
    |
 LL | use Foo::C2;
-   |     ^^^ Not a module `Foo`
+   |     ^^^ not a module `Foo`
 
 error: aborting due to 5 previous errors
 
diff --git a/src/test/ui/use/use-mod/use-mod-4.stderr b/src/test/ui/use/use-mod/use-mod-4.stderr
index 9a6d608faac..33366b2457b 100644
--- a/src/test/ui/use/use-mod/use-mod-4.stderr
+++ b/src/test/ui/use/use-mod/use-mod-4.stderr
@@ -14,7 +14,7 @@ error[E0432]: unresolved import `foo`
   --> $DIR/use-mod-4.rs:11:5
    |
 LL | use foo::self; //~ ERROR unresolved import `foo`
-   |     ^^^ Maybe a missing `extern crate foo;`?
+   |     ^^^ maybe a missing `extern crate foo;`?
 
 error: aborting due to 3 previous errors
 
diff --git a/src/test/ui/use/use-self-type.rs b/src/test/ui/use/use-self-type.rs
index 6b5286bf0a7..1b49d358261 100644
--- a/src/test/ui/use/use-self-type.rs
+++ b/src/test/ui/use/use-self-type.rs
@@ -14,7 +14,7 @@ impl S {
     fn f() {}
     fn g() {
         use Self::f; //~ ERROR unresolved import
-        pub(in Self::f) struct Z; //~ ERROR Use of undeclared type or module `Self`
+        pub(in Self::f) struct Z; //~ ERROR use of undeclared type or module `Self`
     }
 }
 
diff --git a/src/test/ui/use/use-self-type.stderr b/src/test/ui/use/use-self-type.stderr
index 5a1e5ea2595..e4cb0f9f3d8 100644
--- a/src/test/ui/use/use-self-type.stderr
+++ b/src/test/ui/use/use-self-type.stderr
@@ -1,14 +1,14 @@
-error[E0433]: failed to resolve. Use of undeclared type or module `Self`
+error[E0433]: failed to resolve: use of undeclared type or module `Self`
   --> $DIR/use-self-type.rs:17:16
    |
-LL |         pub(in Self::f) struct Z; //~ ERROR Use of undeclared type or module `Self`
-   |                ^^^^ Use of undeclared type or module `Self`
+LL |         pub(in Self::f) struct Z; //~ ERROR use of undeclared type or module `Self`
+   |                ^^^^ use of undeclared type or module `Self`
 
 error[E0432]: unresolved import `Self`
   --> $DIR/use-self-type.rs:16:13
    |
 LL |         use Self::f; //~ ERROR unresolved import
-   |             ^^^^ Use of undeclared type or module `Self`
+   |             ^^^^ use of undeclared type or module `Self`
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/use/use-super-global-path.stderr b/src/test/ui/use/use-super-global-path.stderr
index 4730653dbf9..fc4455c7d6e 100644
--- a/src/test/ui/use/use-super-global-path.stderr
+++ b/src/test/ui/use/use-super-global-path.stderr
@@ -1,10 +1,10 @@
-error[E0433]: failed to resolve. global paths cannot start with `super`
+error[E0433]: failed to resolve: global paths cannot start with `super`
   --> $DIR/use-super-global-path.rs:17:11
    |
 LL |     use ::super::{S, Z}; //~ ERROR global paths cannot start with `super`
    |           ^^^^^ global paths cannot start with `super`
 
-error[E0433]: failed to resolve. global paths cannot start with `super`
+error[E0433]: failed to resolve: global paths cannot start with `super`
   --> $DIR/use-super-global-path.rs:20:15
    |
 LL |         use ::super::main; //~ ERROR global paths cannot start with `super`