error: incorrect `type` inside `extern` block
  --> $DIR/issue-112363-extern-item-where-clauses-debug-ice.rs:2:10
   |
LL | extern "C" {
   | ---------- `extern` blocks define existing foreign types and types inside of them cannot have a body
LL |     type Item = [T] where [T]: Sized;
   |          ^^^^   --- the invalid body
   |          |
   |          cannot have a body
   |
   = note: for more information, visit https://doc.rust-lang.org/std/keyword.extern.html

error: `type`s inside `extern` blocks cannot have `where` clauses
  --> $DIR/issue-112363-extern-item-where-clauses-debug-ice.rs:2:21
   |
LL | extern "C" {
   | ---------- `extern` block begins here
LL |     type Item = [T] where [T]: Sized;
   |                     ^^^^^^^^^^^^^^^^ help: remove the `where` clause
   |
   = note: for more information, visit https://doc.rust-lang.org/std/keyword.extern.html

error[E0412]: cannot find type `T` in this scope
  --> $DIR/issue-112363-extern-item-where-clauses-debug-ice.rs:2:28
   |
LL |     type Item = [T] where [T]: Sized;
   |                            ^ not found in this scope

error[E0412]: cannot find type `T` in this scope
  --> $DIR/issue-112363-extern-item-where-clauses-debug-ice.rs:2:18
   |
LL |     type Item = [T] where [T]: Sized;
   |                  ^ not found in this scope

error[E0658]: extern types are experimental
  --> $DIR/issue-112363-extern-item-where-clauses-debug-ice.rs:2:5
   |
LL |     type Item = [T] where [T]: Sized;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: see issue #43467 <https://github.com/rust-lang/rust/issues/43467> for more information
   = help: add `#![feature(extern_types)]` to the crate attributes to enable
   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date

error: aborting due to 5 previous errors

Some errors have detailed explanations: E0412, E0658.
For more information about an error, try `rustc --explain E0412`.