2 files changed, 44 insertions, 3 deletions
diff --git a/tests/ui/macros/issue-78325-inconsistent-resolution.rs b/tests/ui/macros/issue-78325-inconsistent-resolution.rs
index 919eca4f9bf..021ba599d12 100644
--- a/tests/ui/macros/issue-78325-inconsistent-resolution.rs
+++ b/tests/ui/macros/issue-78325-inconsistent-resolution.rs
@@ -1,3 +1,5 @@
+//@ edition: 2018
+
 macro_rules! define_other_core {
     ( ) => {
         extern crate std as core;
@@ -6,7 +8,8 @@ macro_rules! define_other_core {
 }
 
 fn main() {
-    core::panic!();
+    core::panic!(); //~ ERROR `core` is ambiguous
+    ::core::panic!(); //~ ERROR `core` is ambiguous
 }
 
 define_other_core!();
diff --git a/tests/ui/macros/issue-78325-inconsistent-resolution.stderr b/tests/ui/macros/issue-78325-inconsistent-resolution.stderr
index b75e4a9c9e0..7c745040640 100644
--- a/tests/ui/macros/issue-78325-inconsistent-resolution.stderr
+++ b/tests/ui/macros/issue-78325-inconsistent-resolution.stderr
@@ -1,5 +1,5 @@
 error: macro-expanded `extern crate` items cannot shadow names passed with `--extern`
-  --> $DIR/issue-78325-inconsistent-resolution.rs:3:9
+  --> $DIR/issue-78325-inconsistent-resolution.rs:5:9
    |
 LL |         extern crate std as core;
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -9,5 +9,43 @@ LL | define_other_core!();
    |
    = note: this error originates in the macro `define_other_core` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to 1 previous error
+error[E0659]: `core` is ambiguous
+  --> $DIR/issue-78325-inconsistent-resolution.rs:11:5
+   |
+LL |     core::panic!();
+   |     ^^^^ ambiguous name
+   |
+   = note: ambiguous because of a conflict between a macro-expanded name and a less macro-expanded name from outer scope during import or macro resolution
+   = note: `core` could refer to a built-in crate
+note: `core` could also refer to the crate imported here
+  --> $DIR/issue-78325-inconsistent-resolution.rs:5:9
+   |
+LL |         extern crate std as core;
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^
+...
+LL | define_other_core!();
+   | -------------------- in this macro invocation
+   = help: use `crate::core` to refer to this crate unambiguously
+   = note: this error originates in the macro `define_other_core` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0659]: `core` is ambiguous
+  --> $DIR/issue-78325-inconsistent-resolution.rs:12:7
+   |
+LL |     ::core::panic!();
+   |       ^^^^ ambiguous name
+   |
+   = note: ambiguous because of a conflict between a macro-expanded name and a less macro-expanded name from outer scope during import or macro resolution
+   = note: `core` could refer to a built-in crate
+note: `core` could also refer to the crate imported here
+  --> $DIR/issue-78325-inconsistent-resolution.rs:5:9
+   |
+LL |         extern crate std as core;
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^
+...
+LL | define_other_core!();
+   | -------------------- in this macro invocation
+   = note: this error originates in the macro `define_other_core` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 3 previous errors
 
+For more information about this error, try `rustc --explain E0659`.