Auto merge of #90203 - matthiaskrgr:rollup-v215wew, r=matthiaskrgr

Rollup of 5 pull requests

Successful merges:

 - #85833 (Scrape code examples from examples/ directory for Rustdoc)
 - #88041 (Make all proc-macro back-compat lints deny-by-default)
 - #89829 (Consider types appearing in const expressions to be invariant)
 - #90168 (Reset qualifs when a storage of a local ends)
 - #90198 (Add caveat about changing parallelism and function call overhead)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

15 files changed, 136 insertions, 111 deletions

diff --git a/src/test/ui/const-generics/issues/issue-67375.full.stderr b/src/test/ui/const-generics/issues/issue-67375.full.stderr
index 0f0e339655b..0cf69879a5c 100644
--- a/src/test/ui/const-generics/issues/issue-67375.full.stderr
+++ b/src/test/ui/const-generics/issues/issue-67375.full.stderr
@@ -8,15 +8,5 @@ LL |     inner: [(); { [|_: &T| {}; 0].len() }],
    |
    = help: consider moving this anonymous constant into a `const` function
 
-error[E0392]: parameter `T` is never used
-  --> $DIR/issue-67375.rs:5:12
-   |
-LL | struct Bug<T> {
-   |            ^ unused parameter
-   |
-   = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData`
-   = help: if you intended `T` to be a const parameter, use `const T: usize` instead
-
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0392`.
diff --git a/src/test/ui/const-generics/issues/issue-67375.rs b/src/test/ui/const-generics/issues/issue-67375.rs
index b5b842a15ae..8b4b276bae0 100644
--- a/src/test/ui/const-generics/issues/issue-67375.rs
+++ b/src/test/ui/const-generics/issues/issue-67375.rs
@@ -3,7 +3,7 @@
 #![cfg_attr(full, feature(generic_const_exprs))]
 
 struct Bug<T> {
-    //~^ ERROR parameter `T` is never used
+    //[min]~^ ERROR parameter `T` is never used
     inner: [(); { [|_: &T| {}; 0].len() }],
     //[min]~^ ERROR generic parameters may not be used in const operations
     //[full]~^^ ERROR overly complex generic constant
diff --git a/src/test/ui/const-generics/issues/issue-67945-1.full.stderr b/src/test/ui/const-generics/issues/issue-67945-1.full.stderr
index 1edc7828caa..8e18fcdffab 100644
--- a/src/test/ui/const-generics/issues/issue-67945-1.full.stderr
+++ b/src/test/ui/const-generics/issues/issue-67945-1.full.stderr
@@ -12,16 +12,6 @@ LL |         let x: S = MaybeUninit::uninit();
    = note: expected type parameter `S`
                        found union `MaybeUninit<_>`
 
-error[E0392]: parameter `S` is never used
-  --> $DIR/issue-67945-1.rs:7:12
-   |
-LL | struct Bug<S> {
-   |            ^ unused parameter
-   |
-   = help: consider removing `S`, referring to it in a field, or using a marker such as `PhantomData`
-   = help: if you intended `S` to be a const parameter, use `const S: usize` instead
-
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-Some errors have detailed explanations: E0308, E0392.
-For more information about an error, try `rustc --explain E0308`.
+For more information about this error, try `rustc --explain E0308`.
diff --git a/src/test/ui/const-generics/issues/issue-67945-1.rs b/src/test/ui/const-generics/issues/issue-67945-1.rs
index 7b7e8428639..99f88bc8e10 100644
--- a/src/test/ui/const-generics/issues/issue-67945-1.rs
+++ b/src/test/ui/const-generics/issues/issue-67945-1.rs
@@ -5,7 +5,7 @@
 use std::mem::MaybeUninit;
 
 struct Bug<S> {
-    //~^ ERROR parameter `S` is never used
+    //[min]~^ ERROR parameter `S` is never used
     A: [(); {
         let x: S = MaybeUninit::uninit();
         //[min]~^ ERROR generic parameters may not be used in const operations
diff --git a/src/test/ui/consts/promoted-storage.rs b/src/test/ui/consts/promoted-storage.rs
new file mode 100644
index 00000000000..52ef685e8f4
--- /dev/null
+++ b/src/test/ui/consts/promoted-storage.rs
@@ -0,0 +1,20 @@
+// Check that storage statements reset local qualification.
+// check-pass
+use std::cell::Cell;
+
+const C: Option<Cell<u32>> = {
+    let mut c = None;
+    let mut i = 0;
+    while i == 0 {
+        let mut x = None;
+        c = x;
+        x = Some(Cell::new(0));
+        let _ = x;
+        i += 1;
+    }
+    c
+};
+
+fn main() {
+    let _: &'static _ = &C;
+}
diff --git a/src/test/ui/proc-macro/generate-mod.rs b/src/test/ui/proc-macro/generate-mod.rs
index e5f967416c9..471f317edf9 100644
--- a/src/test/ui/proc-macro/generate-mod.rs
+++ b/src/test/ui/proc-macro/generate-mod.rs
@@ -13,15 +13,15 @@ generate_mod::check!(); //~ ERROR cannot find type `FromOutside` in this scope
                             //~| ERROR cannot find type `OuterAttr` in this scope
 struct S;
 
-#[derive(generate_mod::CheckDerive)] //~ WARN cannot find type `FromOutside` in this scope
-                                     //~| WARN cannot find type `OuterDerive` in this scope
+#[derive(generate_mod::CheckDerive)] //~ ERROR cannot find type `FromOutside` in this scope
+                                     //~| ERROR cannot find type `OuterDerive` in this scope
                                      //~| WARN this was previously accepted
                                      //~| WARN this was previously accepted
 struct Z;
 
 fn inner_block() {
-    #[derive(generate_mod::CheckDerive)] //~ WARN cannot find type `FromOutside` in this scope
-                                        //~| WARN cannot find type `OuterDerive` in this scope
+    #[derive(generate_mod::CheckDerive)] //~ ERROR cannot find type `FromOutside` in this scope
+                                        //~| ERROR cannot find type `OuterDerive` in this scope
                                         //~| WARN this was previously accepted
                                         //~| WARN this was previously accepted
     struct InnerZ;
diff --git a/src/test/ui/proc-macro/generate-mod.stderr b/src/test/ui/proc-macro/generate-mod.stderr
index be58cc40ed2..a2c1b82b15f 100644
--- a/src/test/ui/proc-macro/generate-mod.stderr
+++ b/src/test/ui/proc-macro/generate-mod.stderr
@@ -38,18 +38,18 @@ LL | #[generate_mod::check_attr]
            OuterAttr
    = note: this error originates in the attribute macro `generate_mod::check_attr` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-warning: cannot find type `FromOutside` in this scope
+error: cannot find type `FromOutside` in this scope
   --> $DIR/generate-mod.rs:16:10
    |
 LL | #[derive(generate_mod::CheckDerive)]
    |          ^^^^^^^^^^^^^^^^^^^^^^^^^ names from parent modules are not accessible without an explicit import
    |
-   = note: `#[warn(proc_macro_derive_resolution_fallback)]` on by default
+   = note: `#[deny(proc_macro_derive_resolution_fallback)]` on by default
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83583 <https://github.com/rust-lang/rust/issues/83583>
-   = note: this warning originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-warning: cannot find type `OuterDerive` in this scope
+error: cannot find type `OuterDerive` in this scope
   --> $DIR/generate-mod.rs:16:10
    |
 LL | #[derive(generate_mod::CheckDerive)]
@@ -57,9 +57,9 @@ LL | #[derive(generate_mod::CheckDerive)]
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83583 <https://github.com/rust-lang/rust/issues/83583>
-   = note: this warning originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-warning: cannot find type `FromOutside` in this scope
+error: cannot find type `FromOutside` in this scope
   --> $DIR/generate-mod.rs:23:14
    |
 LL |     #[derive(generate_mod::CheckDerive)]
@@ -67,9 +67,9 @@ LL |     #[derive(generate_mod::CheckDerive)]
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83583 <https://github.com/rust-lang/rust/issues/83583>
-   = note: this warning originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-warning: cannot find type `OuterDerive` in this scope
+error: cannot find type `OuterDerive` in this scope
   --> $DIR/generate-mod.rs:23:14
    |
 LL |     #[derive(generate_mod::CheckDerive)]
@@ -77,25 +77,25 @@ LL |     #[derive(generate_mod::CheckDerive)]
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83583 <https://github.com/rust-lang/rust/issues/83583>
-   = note: this warning originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to 4 previous errors; 4 warnings emitted
+error: aborting due to 8 previous errors
 
 For more information about this error, try `rustc --explain E0412`.
 Future incompatibility report: Future breakage diagnostic:
-warning: cannot find type `FromOutside` in this scope
+error: cannot find type `FromOutside` in this scope
   --> $DIR/generate-mod.rs:16:10
    |
 LL | #[derive(generate_mod::CheckDerive)]
    |          ^^^^^^^^^^^^^^^^^^^^^^^^^ names from parent modules are not accessible without an explicit import
    |
-   = note: `#[warn(proc_macro_derive_resolution_fallback)]` on by default
+   = note: `#[deny(proc_macro_derive_resolution_fallback)]` on by default
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83583 <https://github.com/rust-lang/rust/issues/83583>
-   = note: this warning originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 Future breakage diagnostic:
-warning: cannot find type `OuterDerive` in this scope
+error: cannot find type `OuterDerive` in this scope
   --> $DIR/generate-mod.rs:16:10
    |
 LL | #[derive(generate_mod::CheckDerive)]
@@ -103,10 +103,10 @@ LL | #[derive(generate_mod::CheckDerive)]
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83583 <https://github.com/rust-lang/rust/issues/83583>
-   = note: this warning originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 Future breakage diagnostic:
-warning: cannot find type `FromOutside` in this scope
+error: cannot find type `FromOutside` in this scope
   --> $DIR/generate-mod.rs:23:14
    |
 LL |     #[derive(generate_mod::CheckDerive)]
@@ -114,10 +114,10 @@ LL |     #[derive(generate_mod::CheckDerive)]
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83583 <https://github.com/rust-lang/rust/issues/83583>
-   = note: this warning originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 Future breakage diagnostic:
-warning: cannot find type `OuterDerive` in this scope
+error: cannot find type `OuterDerive` in this scope
   --> $DIR/generate-mod.rs:23:14
    |
 LL |     #[derive(generate_mod::CheckDerive)]
@@ -125,7 +125,7 @@ LL |     #[derive(generate_mod::CheckDerive)]
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83583 <https://github.com/rust-lang/rust/issues/83583>
-   = note: this warning originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 Future breakage diagnostic:
 warning: cannot find type `FromOutside` in this scope
diff --git a/src/test/ui/proc-macro/group-compat-hack/group-compat-hack.rs b/src/test/ui/proc-macro/group-compat-hack/group-compat-hack.rs
index 2b742771d6f..3a2a6fa2253 100644
--- a/src/test/ui/proc-macro/group-compat-hack/group-compat-hack.rs
+++ b/src/test/ui/proc-macro/group-compat-hack/group-compat-hack.rs
@@ -1,4 +1,3 @@
-// check-pass
 // aux-build:pin-project-internal-0.4.0.rs
 // compile-flags: -Z span-debug
 
@@ -24,7 +23,7 @@ mod no_version {
     }
 
     struct Foo;
-    impl_macros!(Foo); //~ WARN  using an old version
+    impl_macros!(Foo); //~ ERROR  using an old version
                        //~| WARN this was previously
     arrays!(Foo);
     other!(Foo);
@@ -41,9 +40,9 @@ mod with_version {
     }
 
     struct Foo;
-    impl_macros!(Foo); //~  WARN using an old version
+    impl_macros!(Foo); //~  ERROR using an old version
                        //~| WARN this was previously
-    arrays!(Foo); //~  WARN using an old version
+    arrays!(Foo); //~  ERROR using an old version
                   //~| WARN this was previously
     other!(Foo);
 }
@@ -52,7 +51,7 @@ mod actix_web_test {
     include!("actix-web/src/extract.rs");
 
     struct Foo;
-    tuple_from_req!(Foo); //~ WARN using an old version
+    tuple_from_req!(Foo); //~ ERROR using an old version
     //~| WARN this was previously
 }
 
@@ -60,7 +59,7 @@ mod actix_web_version_test {
     include!("actix-web-2.0.0/src/extract.rs");
 
     struct Foo;
-    tuple_from_req!(Foo); //~ WARN using an old version
+    tuple_from_req!(Foo); //~ ERROR using an old version
     //~| WARN this was previously
 }
 
diff --git a/src/test/ui/proc-macro/group-compat-hack/group-compat-hack.stderr b/src/test/ui/proc-macro/group-compat-hack/group-compat-hack.stderr
index 1a56291896c..bd9ba6a09fc 100644
--- a/src/test/ui/proc-macro/group-compat-hack/group-compat-hack.stderr
+++ b/src/test/ui/proc-macro/group-compat-hack/group-compat-hack.stderr
@@ -1,27 +1,27 @@
-warning: using an old version of `time-macros-impl`
+error: using an old version of `time-macros-impl`
   --> $DIR/time-macros-impl/src/lib.rs:5:32
    |
 LL |         #[my_macro] struct One($name);
    |                                ^^^^^
    |
-  ::: $DIR/group-compat-hack.rs:27:5
+  ::: $DIR/group-compat-hack.rs:26:5
    |
 LL |     impl_macros!(Foo);
    |     ----------------- in this macro invocation
    |
-   = note: `#[warn(proc_macro_back_compat)]` on by default
+   = note: `#[deny(proc_macro_back_compat)]` on by default
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83125 <https://github.com/rust-lang/rust/issues/83125>
    = note: the `time-macros-impl` crate will stop compiling in futures version of Rust. Please update to the latest version of the `time` crate to avoid breakage
-   = note: this warning originates in the macro `impl_macros` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `impl_macros` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-warning: using an old version of `time-macros-impl`
+error: using an old version of `time-macros-impl`
   --> $DIR/time-macros-impl-0.1.0/src/lib.rs:5:32
    |
 LL |         #[my_macro] struct One($name);
    |                                ^^^^^
    |
-  ::: $DIR/group-compat-hack.rs:44:5
+  ::: $DIR/group-compat-hack.rs:43:5
    |
 LL |     impl_macros!(Foo);
    |     ----------------- in this macro invocation
@@ -29,15 +29,15 @@ LL |     impl_macros!(Foo);
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83125 <https://github.com/rust-lang/rust/issues/83125>
    = note: the `time-macros-impl` crate will stop compiling in futures version of Rust. Please update to the latest version of the `time` crate to avoid breakage
-   = note: this warning originates in the macro `impl_macros` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `impl_macros` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-warning: using an old version of `js-sys`
+error: using an old version of `js-sys`
   --> $DIR/js-sys-0.3.17/src/lib.rs:5:32
    |
 LL |         #[my_macro] struct Two($name);
    |                                ^^^^^
    |
-  ::: $DIR/group-compat-hack.rs:46:5
+  ::: $DIR/group-compat-hack.rs:45:5
    |
 LL |     arrays!(Foo);
    |     ------------ in this macro invocation
@@ -45,15 +45,15 @@ LL |     arrays!(Foo);
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83125 <https://github.com/rust-lang/rust/issues/83125>
    = note: older versions of the `js-sys` crate will stop compiling in future versions of Rust; please update to `js-sys` v0.3.40 or above
-   = note: this warning originates in the macro `arrays` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `arrays` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-warning: using an old version of `actix-web`
+error: using an old version of `actix-web`
   --> $DIR/actix-web/src/extract.rs:5:34
    |
 LL |         #[my_macro] struct Three($T);
    |                                  ^^
    |
-  ::: $DIR/group-compat-hack.rs:55:5
+  ::: $DIR/group-compat-hack.rs:54:5
    |
 LL |     tuple_from_req!(Foo);
    |     -------------------- in this macro invocation
@@ -61,15 +61,15 @@ LL |     tuple_from_req!(Foo);
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83125 <https://github.com/rust-lang/rust/issues/83125>
    = note: the version of `actix-web` you are using might stop compiling in future versions of Rust; please update to the latest version of the `actix-web` crate to avoid breakage
-   = note: this warning originates in the macro `tuple_from_req` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `tuple_from_req` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-warning: using an old version of `actix-web`
+error: using an old version of `actix-web`
   --> $DIR/actix-web-2.0.0/src/extract.rs:5:34
    |
 LL |         #[my_macro] struct Three($T);
    |                                  ^^
    |
-  ::: $DIR/group-compat-hack.rs:63:5
+  ::: $DIR/group-compat-hack.rs:62:5
    |
 LL |     tuple_from_req!(Foo);
    |     -------------------- in this macro invocation
@@ -77,36 +77,36 @@ LL |     tuple_from_req!(Foo);
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83125 <https://github.com/rust-lang/rust/issues/83125>
    = note: the version of `actix-web` you are using might stop compiling in future versions of Rust; please update to the latest version of the `actix-web` crate to avoid breakage
-   = note: this warning originates in the macro `tuple_from_req` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `tuple_from_req` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-warning: 5 warnings emitted
+error: aborting due to 5 previous errors
 
 Future incompatibility report: Future breakage diagnostic:
-warning: using an old version of `time-macros-impl`
+error: using an old version of `time-macros-impl`
   --> $DIR/time-macros-impl/src/lib.rs:5:32
    |
 LL |         #[my_macro] struct One($name);
    |                                ^^^^^
    |
-  ::: $DIR/group-compat-hack.rs:27:5
+  ::: $DIR/group-compat-hack.rs:26:5
    |
 LL |     impl_macros!(Foo);
    |     ----------------- in this macro invocation
    |
-   = note: `#[warn(proc_macro_back_compat)]` on by default
+   = note: `#[deny(proc_macro_back_compat)]` on by default
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83125 <https://github.com/rust-lang/rust/issues/83125>
    = note: the `time-macros-impl` crate will stop compiling in futures version of Rust. Please update to the latest version of the `time` crate to avoid breakage
-   = note: this warning originates in the macro `impl_macros` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `impl_macros` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 Future breakage diagnostic:
-warning: using an old version of `time-macros-impl`
+error: using an old version of `time-macros-impl`
   --> $DIR/time-macros-impl-0.1.0/src/lib.rs:5:32
    |
 LL |         #[my_macro] struct One($name);
    |                                ^^^^^
    |
-  ::: $DIR/group-compat-hack.rs:44:5
+  ::: $DIR/group-compat-hack.rs:43:5
    |
 LL |     impl_macros!(Foo);
    |     ----------------- in this macro invocation
@@ -114,16 +114,16 @@ LL |     impl_macros!(Foo);
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83125 <https://github.com/rust-lang/rust/issues/83125>
    = note: the `time-macros-impl` crate will stop compiling in futures version of Rust. Please update to the latest version of the `time` crate to avoid breakage
-   = note: this warning originates in the macro `impl_macros` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `impl_macros` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 Future breakage diagnostic:
-warning: using an old version of `js-sys`
+error: using an old version of `js-sys`
   --> $DIR/js-sys-0.3.17/src/lib.rs:5:32
    |
 LL |         #[my_macro] struct Two($name);
    |                                ^^^^^
    |
-  ::: $DIR/group-compat-hack.rs:46:5
+  ::: $DIR/group-compat-hack.rs:45:5
    |
 LL |     arrays!(Foo);
    |     ------------ in this macro invocation
@@ -131,16 +131,16 @@ LL |     arrays!(Foo);
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83125 <https://github.com/rust-lang/rust/issues/83125>
    = note: older versions of the `js-sys` crate will stop compiling in future versions of Rust; please update to `js-sys` v0.3.40 or above
-   = note: this warning originates in the macro `arrays` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `arrays` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 Future breakage diagnostic:
-warning: using an old version of `actix-web`
+error: using an old version of `actix-web`
   --> $DIR/actix-web/src/extract.rs:5:34
    |
 LL |         #[my_macro] struct Three($T);
    |                                  ^^
    |
-  ::: $DIR/group-compat-hack.rs:55:5
+  ::: $DIR/group-compat-hack.rs:54:5
    |
 LL |     tuple_from_req!(Foo);
    |     -------------------- in this macro invocation
@@ -148,16 +148,16 @@ LL |     tuple_from_req!(Foo);
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83125 <https://github.com/rust-lang/rust/issues/83125>
    = note: the version of `actix-web` you are using might stop compiling in future versions of Rust; please update to the latest version of the `actix-web` crate to avoid breakage
-   = note: this warning originates in the macro `tuple_from_req` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `tuple_from_req` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 Future breakage diagnostic:
-warning: using an old version of `actix-web`
+error: using an old version of `actix-web`
   --> $DIR/actix-web-2.0.0/src/extract.rs:5:34
    |
 LL |         #[my_macro] struct Three($T);
    |                                  ^^
    |
-  ::: $DIR/group-compat-hack.rs:63:5
+  ::: $DIR/group-compat-hack.rs:62:5
    |
 LL |     tuple_from_req!(Foo);
    |     -------------------- in this macro invocation
@@ -165,5 +165,5 @@ LL |     tuple_from_req!(Foo);
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83125 <https://github.com/rust-lang/rust/issues/83125>
    = note: the version of `actix-web` you are using might stop compiling in future versions of Rust; please update to the latest version of the `actix-web` crate to avoid breakage
-   = note: this warning originates in the macro `tuple_from_req` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `tuple_from_req` (in Nightly builds, run with -Z macro-backtrace for more info)
 
diff --git a/src/test/ui/proc-macro/group-compat-hack/group-compat-hack.stdout b/src/test/ui/proc-macro/group-compat-hack/group-compat-hack.stdout
index 82d6bc33bf9..51312b10ad1 100644
--- a/src/test/ui/proc-macro/group-compat-hack/group-compat-hack.stdout
+++ b/src/test/ui/proc-macro/group-compat-hack/group-compat-hack.stdout
@@ -1,11 +1,11 @@
-Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/time-macros-impl/src/lib.rs:5:21: 5:27 (#6) }, Ident { ident: "One", span: $DIR/time-macros-impl/src/lib.rs:5:28: 5:31 (#6) }, Group { delimiter: Parenthesis, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:27:18: 27:21 (#0) }], span: $DIR/time-macros-impl/src/lib.rs:5:31: 5:38 (#6) }, Punct { ch: ';', spacing: Alone, span: $DIR/time-macros-impl/src/lib.rs:5:38: 5:39 (#6) }]
-Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/js-sys/src/lib.rs:5:21: 5:27 (#10) }, Ident { ident: "Two", span: $DIR/js-sys/src/lib.rs:5:28: 5:31 (#10) }, Group { delimiter: Parenthesis, stream: TokenStream [Group { delimiter: None, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:29:13: 29:16 (#0) }], span: $DIR/js-sys/src/lib.rs:5:32: 5:37 (#10) }], span: $DIR/js-sys/src/lib.rs:5:31: 5:38 (#10) }, Punct { ch: ';', spacing: Alone, span: $DIR/js-sys/src/lib.rs:5:38: 5:39 (#10) }]
-Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/group-compat-hack.rs:22:25: 22:31 (#14) }, Ident { ident: "Three", span: $DIR/group-compat-hack.rs:22:32: 22:37 (#14) }, Group { delimiter: Parenthesis, stream: TokenStream [Group { delimiter: None, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:30:12: 30:15 (#0) }], span: $DIR/group-compat-hack.rs:22:38: 22:43 (#14) }], span: $DIR/group-compat-hack.rs:22:37: 22:44 (#14) }, Punct { ch: ';', spacing: Alone, span: $DIR/group-compat-hack.rs:22:44: 22:45 (#14) }]
-Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/time-macros-impl-0.1.0/src/lib.rs:5:21: 5:27 (#20) }, Ident { ident: "One", span: $DIR/time-macros-impl-0.1.0/src/lib.rs:5:28: 5:31 (#20) }, Group { delimiter: Parenthesis, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:44:18: 44:21 (#0) }], span: $DIR/time-macros-impl-0.1.0/src/lib.rs:5:31: 5:38 (#20) }, Punct { ch: ';', spacing: Alone, span: $DIR/time-macros-impl-0.1.0/src/lib.rs:5:38: 5:39 (#20) }]
-Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/js-sys-0.3.17/src/lib.rs:5:21: 5:27 (#24) }, Ident { ident: "Two", span: $DIR/js-sys-0.3.17/src/lib.rs:5:28: 5:31 (#24) }, Group { delimiter: Parenthesis, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:46:13: 46:16 (#0) }], span: $DIR/js-sys-0.3.17/src/lib.rs:5:31: 5:38 (#24) }, Punct { ch: ';', spacing: Alone, span: $DIR/js-sys-0.3.17/src/lib.rs:5:38: 5:39 (#24) }]
-Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/group-compat-hack.rs:39:25: 39:31 (#28) }, Ident { ident: "Three", span: $DIR/group-compat-hack.rs:39:32: 39:37 (#28) }, Group { delimiter: Parenthesis, stream: TokenStream [Group { delimiter: None, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:48:12: 48:15 (#0) }], span: $DIR/group-compat-hack.rs:39:38: 39:43 (#28) }], span: $DIR/group-compat-hack.rs:39:37: 39:44 (#28) }, Punct { ch: ';', spacing: Alone, span: $DIR/group-compat-hack.rs:39:44: 39:45 (#28) }]
-Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/actix-web/src/extract.rs:5:21: 5:27 (#33) }, Ident { ident: "Three", span: $DIR/actix-web/src/extract.rs:5:28: 5:33 (#33) }, Group { delimiter: Parenthesis, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:55:21: 55:24 (#0) }], span: $DIR/actix-web/src/extract.rs:5:33: 5:37 (#33) }, Punct { ch: ';', spacing: Alone, span: $DIR/actix-web/src/extract.rs:5:37: 5:38 (#33) }]
-Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/actix-web-2.0.0/src/extract.rs:5:21: 5:27 (#38) }, Ident { ident: "Three", span: $DIR/actix-web-2.0.0/src/extract.rs:5:28: 5:33 (#38) }, Group { delimiter: Parenthesis, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:63:21: 63:24 (#0) }], span: $DIR/actix-web-2.0.0/src/extract.rs:5:33: 5:37 (#38) }, Punct { ch: ';', spacing: Alone, span: $DIR/actix-web-2.0.0/src/extract.rs:5:37: 5:38 (#38) }]
-Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/actori-web/src/extract.rs:5:21: 5:27 (#43) }, Ident { ident: "Four", span: $DIR/actori-web/src/extract.rs:5:28: 5:32 (#43) }, Group { delimiter: Parenthesis, stream: TokenStream [Group { delimiter: None, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:71:21: 71:24 (#0) }], span: $DIR/actori-web/src/extract.rs:5:33: 5:35 (#43) }], span: $DIR/actori-web/src/extract.rs:5:32: 5:36 (#43) }, Punct { ch: ';', spacing: Alone, span: $DIR/actori-web/src/extract.rs:5:36: 5:37 (#43) }]
-Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/actori-web-2.0.0/src/extract.rs:5:21: 5:27 (#48) }, Ident { ident: "Four", span: $DIR/actori-web-2.0.0/src/extract.rs:5:28: 5:32 (#48) }, Group { delimiter: Parenthesis, stream: TokenStream [Group { delimiter: None, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:78:21: 78:24 (#0) }], span: $DIR/actori-web-2.0.0/src/extract.rs:5:33: 5:35 (#48) }], span: $DIR/actori-web-2.0.0/src/extract.rs:5:32: 5:36 (#48) }, Punct { ch: ';', spacing: Alone, span: $DIR/actori-web-2.0.0/src/extract.rs:5:36: 5:37 (#48) }]
-Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/js-sys-0.3.40/src/lib.rs:5:21: 5:27 (#53) }, Ident { ident: "Two", span: $DIR/js-sys-0.3.40/src/lib.rs:5:28: 5:31 (#53) }, Group { delimiter: Parenthesis, stream: TokenStream [Group { delimiter: None, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:84:13: 84:16 (#0) }], span: $DIR/js-sys-0.3.40/src/lib.rs:5:32: 5:37 (#53) }], span: $DIR/js-sys-0.3.40/src/lib.rs:5:31: 5:38 (#53) }, Punct { ch: ';', spacing: Alone, span: $DIR/js-sys-0.3.40/src/lib.rs:5:38: 5:39 (#53) }]
+Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/time-macros-impl/src/lib.rs:5:21: 5:27 (#6) }, Ident { ident: "One", span: $DIR/time-macros-impl/src/lib.rs:5:28: 5:31 (#6) }, Group { delimiter: Parenthesis, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:26:18: 26:21 (#0) }], span: $DIR/time-macros-impl/src/lib.rs:5:31: 5:38 (#6) }, Punct { ch: ';', spacing: Alone, span: $DIR/time-macros-impl/src/lib.rs:5:38: 5:39 (#6) }]
+Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/js-sys/src/lib.rs:5:21: 5:27 (#10) }, Ident { ident: "Two", span: $DIR/js-sys/src/lib.rs:5:28: 5:31 (#10) }, Group { delimiter: Parenthesis, stream: TokenStream [Group { delimiter: None, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:28:13: 28:16 (#0) }], span: $DIR/js-sys/src/lib.rs:5:32: 5:37 (#10) }], span: $DIR/js-sys/src/lib.rs:5:31: 5:38 (#10) }, Punct { ch: ';', spacing: Alone, span: $DIR/js-sys/src/lib.rs:5:38: 5:39 (#10) }]
+Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/group-compat-hack.rs:21:25: 21:31 (#14) }, Ident { ident: "Three", span: $DIR/group-compat-hack.rs:21:32: 21:37 (#14) }, Group { delimiter: Parenthesis, stream: TokenStream [Group { delimiter: None, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:29:12: 29:15 (#0) }], span: $DIR/group-compat-hack.rs:21:38: 21:43 (#14) }], span: $DIR/group-compat-hack.rs:21:37: 21:44 (#14) }, Punct { ch: ';', spacing: Alone, span: $DIR/group-compat-hack.rs:21:44: 21:45 (#14) }]
+Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/time-macros-impl-0.1.0/src/lib.rs:5:21: 5:27 (#20) }, Ident { ident: "One", span: $DIR/time-macros-impl-0.1.0/src/lib.rs:5:28: 5:31 (#20) }, Group { delimiter: Parenthesis, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:43:18: 43:21 (#0) }], span: $DIR/time-macros-impl-0.1.0/src/lib.rs:5:31: 5:38 (#20) }, Punct { ch: ';', spacing: Alone, span: $DIR/time-macros-impl-0.1.0/src/lib.rs:5:38: 5:39 (#20) }]
+Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/js-sys-0.3.17/src/lib.rs:5:21: 5:27 (#24) }, Ident { ident: "Two", span: $DIR/js-sys-0.3.17/src/lib.rs:5:28: 5:31 (#24) }, Group { delimiter: Parenthesis, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:45:13: 45:16 (#0) }], span: $DIR/js-sys-0.3.17/src/lib.rs:5:31: 5:38 (#24) }, Punct { ch: ';', spacing: Alone, span: $DIR/js-sys-0.3.17/src/lib.rs:5:38: 5:39 (#24) }]
+Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/group-compat-hack.rs:38:25: 38:31 (#28) }, Ident { ident: "Three", span: $DIR/group-compat-hack.rs:38:32: 38:37 (#28) }, Group { delimiter: Parenthesis, stream: TokenStream [Group { delimiter: None, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:47:12: 47:15 (#0) }], span: $DIR/group-compat-hack.rs:38:38: 38:43 (#28) }], span: $DIR/group-compat-hack.rs:38:37: 38:44 (#28) }, Punct { ch: ';', spacing: Alone, span: $DIR/group-compat-hack.rs:38:44: 38:45 (#28) }]
+Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/actix-web/src/extract.rs:5:21: 5:27 (#33) }, Ident { ident: "Three", span: $DIR/actix-web/src/extract.rs:5:28: 5:33 (#33) }, Group { delimiter: Parenthesis, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:54:21: 54:24 (#0) }], span: $DIR/actix-web/src/extract.rs:5:33: 5:37 (#33) }, Punct { ch: ';', spacing: Alone, span: $DIR/actix-web/src/extract.rs:5:37: 5:38 (#33) }]
+Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/actix-web-2.0.0/src/extract.rs:5:21: 5:27 (#38) }, Ident { ident: "Three", span: $DIR/actix-web-2.0.0/src/extract.rs:5:28: 5:33 (#38) }, Group { delimiter: Parenthesis, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:62:21: 62:24 (#0) }], span: $DIR/actix-web-2.0.0/src/extract.rs:5:33: 5:37 (#38) }, Punct { ch: ';', spacing: Alone, span: $DIR/actix-web-2.0.0/src/extract.rs:5:37: 5:38 (#38) }]
+Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/actori-web/src/extract.rs:5:21: 5:27 (#43) }, Ident { ident: "Four", span: $DIR/actori-web/src/extract.rs:5:28: 5:32 (#43) }, Group { delimiter: Parenthesis, stream: TokenStream [Group { delimiter: None, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:70:21: 70:24 (#0) }], span: $DIR/actori-web/src/extract.rs:5:33: 5:35 (#43) }], span: $DIR/actori-web/src/extract.rs:5:32: 5:36 (#43) }, Punct { ch: ';', spacing: Alone, span: $DIR/actori-web/src/extract.rs:5:36: 5:37 (#43) }]
+Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/actori-web-2.0.0/src/extract.rs:5:21: 5:27 (#48) }, Ident { ident: "Four", span: $DIR/actori-web-2.0.0/src/extract.rs:5:28: 5:32 (#48) }, Group { delimiter: Parenthesis, stream: TokenStream [Group { delimiter: None, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:77:21: 77:24 (#0) }], span: $DIR/actori-web-2.0.0/src/extract.rs:5:33: 5:35 (#48) }], span: $DIR/actori-web-2.0.0/src/extract.rs:5:32: 5:36 (#48) }, Punct { ch: ';', spacing: Alone, span: $DIR/actori-web-2.0.0/src/extract.rs:5:36: 5:37 (#48) }]
+Called proc_macro_hack with TokenStream [Ident { ident: "struct", span: $DIR/js-sys-0.3.40/src/lib.rs:5:21: 5:27 (#53) }, Ident { ident: "Two", span: $DIR/js-sys-0.3.40/src/lib.rs:5:28: 5:31 (#53) }, Group { delimiter: Parenthesis, stream: TokenStream [Group { delimiter: None, stream: TokenStream [Ident { ident: "Foo", span: $DIR/group-compat-hack.rs:83:13: 83:16 (#0) }], span: $DIR/js-sys-0.3.40/src/lib.rs:5:32: 5:37 (#53) }], span: $DIR/js-sys-0.3.40/src/lib.rs:5:31: 5:38 (#53) }, Punct { ch: ';', spacing: Alone, span: $DIR/js-sys-0.3.40/src/lib.rs:5:38: 5:39 (#53) }]
diff --git a/src/test/ui/proc-macro/issue-73933-procedural-masquerade.rs b/src/test/ui/proc-macro/issue-73933-procedural-masquerade.rs
index abc3d2691a3..113235051b2 100644
--- a/src/test/ui/proc-macro/issue-73933-procedural-masquerade.rs
+++ b/src/test/ui/proc-macro/issue-73933-procedural-masquerade.rs
@@ -1,11 +1,10 @@
-// check-pass
 // aux-build:test-macros.rs
 
 #[macro_use]
 extern crate test_macros;
 
 #[derive(Print)]
-enum ProceduralMasqueradeDummyType { //~ WARN using
+enum ProceduralMasqueradeDummyType { //~ ERROR using
 //~| WARN this was previously
     Input
 }
diff --git a/src/test/ui/proc-macro/issue-73933-procedural-masquerade.stderr b/src/test/ui/proc-macro/issue-73933-procedural-masquerade.stderr
index 4d6edab08e2..dff71c9eacd 100644
--- a/src/test/ui/proc-macro/issue-73933-procedural-masquerade.stderr
+++ b/src/test/ui/proc-macro/issue-73933-procedural-masquerade.stderr
@@ -1,24 +1,24 @@
-warning: using `procedural-masquerade` crate
-  --> $DIR/issue-73933-procedural-masquerade.rs:8:6
+error: using `procedural-masquerade` crate
+  --> $DIR/issue-73933-procedural-masquerade.rs:7:6
    |
 LL | enum ProceduralMasqueradeDummyType {
    |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: `#[warn(proc_macro_back_compat)]` on by default
+   = note: `#[deny(proc_macro_back_compat)]` on by default
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83125 <https://github.com/rust-lang/rust/issues/83125>
    = note: The `procedural-masquerade` crate has been unnecessary since Rust 1.30.0. Versions of this crate below 0.1.7 will eventually stop compiling.
 
-warning: 1 warning emitted
+error: aborting due to previous error
 
 Future incompatibility report: Future breakage diagnostic:
-warning: using `procedural-masquerade` crate
-  --> $DIR/issue-73933-procedural-masquerade.rs:8:6
+error: using `procedural-masquerade` crate
+  --> $DIR/issue-73933-procedural-masquerade.rs:7:6
    |
 LL | enum ProceduralMasqueradeDummyType {
    |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: `#[warn(proc_macro_back_compat)]` on by default
+   = note: `#[deny(proc_macro_back_compat)]` on by default
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #83125 <https://github.com/rust-lang/rust/issues/83125>
    = note: The `procedural-masquerade` crate has been unnecessary since Rust 1.30.0. Versions of this crate below 0.1.7 will eventually stop compiling.
diff --git a/src/test/ui/proc-macro/issue-73933-procedural-masquerade.stdout b/src/test/ui/proc-macro/issue-73933-procedural-masquerade.stdout
index 8edd68f8a3b..8a8fbf06824 100644
--- a/src/test/ui/proc-macro/issue-73933-procedural-masquerade.stdout
+++ b/src/test/ui/proc-macro/issue-73933-procedural-masquerade.stdout
@@ -3,20 +3,20 @@ PRINT-DERIVE RE-COLLECTED (DISPLAY): enum ProceduralMasqueradeDummyType { Input
 PRINT-DERIVE INPUT (DEBUG): TokenStream [
     Ident {
         ident: "enum",
-        span: #0 bytes(100..104),
+        span: #0 bytes(86..90),
     },
     Ident {
         ident: "ProceduralMasqueradeDummyType",
-        span: #0 bytes(105..134),
+        span: #0 bytes(91..120),
     },
     Group {
         delimiter: Brace,
         stream: TokenStream [
             Ident {
                 ident: "Input",
-                span: #0 bytes(186..191),
+                span: #0 bytes(173..178),
             },
         ],
-        span: #0 bytes(135..193),
+        span: #0 bytes(121..180),
     },
 ]
diff --git a/src/test/ui/variance/variance-associated-consts.rs b/src/test/ui/variance/variance-associated-consts.rs
new file mode 100644
index 00000000000..da55bc96244
--- /dev/null
+++ b/src/test/ui/variance/variance-associated-consts.rs
@@ -0,0 +1,17 @@
+// Test that the variance computation considers types that
+// appear in const expressions to be invariant.
+
+#![feature(rustc_attrs)]
+#![allow(incomplete_features)]
+#![feature(generic_const_exprs)]
+
+trait Trait {
+    const Const: usize;
+}
+
+#[rustc_variance]
+struct Foo<T: Trait> { //~ ERROR [o]
+    field: [u8; <T as Trait>::Const]
+}
+
+fn main() { }
diff --git a/src/test/ui/variance/variance-associated-consts.stderr b/src/test/ui/variance/variance-associated-consts.stderr
new file mode 100644
index 00000000000..d1bf34781df
--- /dev/null
+++ b/src/test/ui/variance/variance-associated-consts.stderr
@@ -0,0 +1,10 @@
+error[E0208]: [o]
+  --> $DIR/variance-associated-consts.rs:13:1
+   |
+LL | / struct Foo<T: Trait> {
+LL | |     field: [u8; <T as Trait>::Const]
+LL | | }
+   | |_^
+
+error: aborting due to previous error
+