Auto merge of #144458 - compiler-errors:no-witness-mini, r=lcnr

Remove the witness type from coroutine *args* (without actually removing the type)

This does as much of rust-lang/rust#144157 as we can without having to break rust-lang/rust#143545 and/or introduce some better way of handling higher ranked assumptions.

Namely, it:
* Stalls coroutines based off of the *coroutine* type rather than the witness type.
* Reworks the dtorck constraint hack to not rely on the witness type.
* Removes the witness type from the args of the coroutine, eagerly creating the type for nested obligations when needed (auto/clone impls).

I'll experiment with actually removing the witness type in a follow-up.

r? lcnr

18 files changed, 154 insertions, 198 deletions

diff --git a/tests/mir-opt/building/async_await.b-{closure#0}.coroutine_resume.0.mir b/tests/mir-opt/building/async_await.b-{closure#0}.coroutine_resume.0.mir
index 109a41d1ef9..9bff257e063 100644
--- a/tests/mir-opt/building/async_await.b-{closure#0}.coroutine_resume.0.mir
+++ b/tests/mir-opt/building/async_await.b-{closure#0}.coroutine_resume.0.mir
@@ -9,10 +9,6 @@
                     std::future::ResumeTy,
                     (),
                     (),
-                    CoroutineWitness(
-                        DefId(0:5 ~ async_await[ccf8]::a::{closure#0}),
-                        [],
-                    ),
                     (),
                 ],
             ),
@@ -30,10 +26,6 @@
                     std::future::ResumeTy,
                     (),
                     (),
-                    CoroutineWitness(
-                        DefId(0:5 ~ async_await[ccf8]::a::{closure#0}),
-                        [],
-                    ),
                     (),
                 ],
             ),
diff --git a/tests/ui/async-await/async-closures/def-path.stderr b/tests/ui/async-await/async-closures/def-path.stderr
index 58a5b0b79c4..a507fa69760 100644
--- a/tests/ui/async-await/async-closures/def-path.stderr
+++ b/tests/ui/async-await/async-closures/def-path.stderr
@@ -5,11 +5,11 @@ LL |     let x = async || {};
    |                      -- the expected `async` closure body
 LL |
 LL |     let () = x();
-   |         ^^   --- this expression has type `{static main::{closure#0}::{closure#0}<?16t> upvar_tys=?15t resume_ty=ResumeTy yield_ty=() return_ty=() witness={main::{closure#0}::{closure#0}}}`
+   |         ^^   --- this expression has type `{static main::{closure#0}::{closure#0}<?15t> upvar_tys=?14t resume_ty=ResumeTy yield_ty=() return_ty=()}`
    |         |
    |         expected `async` closure body, found `()`
    |
-   = note: expected `async` closure body `{static main::{closure#0}::{closure#0}<?16t> upvar_tys=?15t resume_ty=ResumeTy yield_ty=() return_ty=() witness={main::{closure#0}::{closure#0}}}`
+   = note: expected `async` closure body `{static main::{closure#0}::{closure#0}<?15t> upvar_tys=?14t resume_ty=ResumeTy yield_ty=() return_ty=()}`
                          found unit type `()`
 
 error: aborting due to 1 previous error
diff --git a/tests/ui/async-await/higher-ranked-auto-trait-6.no_assumptions.stderr b/tests/ui/async-await/higher-ranked-auto-trait-6.no_assumptions.stderr
index d1f2d9a0753..d1c88101618 100644
--- a/tests/ui/async-await/higher-ranked-auto-trait-6.no_assumptions.stderr
+++ b/tests/ui/async-await/higher-ranked-auto-trait-6.no_assumptions.stderr
@@ -21,30 +21,6 @@ LL |     Box::new(async { new(|| async { f().await }).await })
    = help: consider pinning your async block and casting it to a trait object
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
-error[E0308]: mismatched types
-  --> $DIR/higher-ranked-auto-trait-6.rs:16:5
-   |
-LL |     Box::new(async { new(|| async { f().await }).await })
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ one type is more general than the other
-   |
-   = note: expected `async` block `{async block@$DIR/higher-ranked-auto-trait-6.rs:16:29: 16:34}`
-              found `async` block `{async block@$DIR/higher-ranked-auto-trait-6.rs:16:29: 16:34}`
-   = note: no two async blocks, even if identical, have the same type
-   = help: consider pinning your async block and casting it to a trait object
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-error[E0308]: mismatched types
-  --> $DIR/higher-ranked-auto-trait-6.rs:16:5
-   |
-LL |     Box::new(async { new(|| async { f().await }).await })
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ one type is more general than the other
-   |
-   = note: expected `async` block `{async block@$DIR/higher-ranked-auto-trait-6.rs:16:29: 16:34}`
-              found `async` block `{async block@$DIR/higher-ranked-auto-trait-6.rs:16:29: 16:34}`
-   = note: no two async blocks, even if identical, have the same type
-   = help: consider pinning your async block and casting it to a trait object
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-error: aborting due to 4 previous errors
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/async-await/issue-70818.rs b/tests/ui/async-await/issue-70818.rs
index bc181de8d92..c11332fe7d8 100644
--- a/tests/ui/async-await/issue-70818.rs
+++ b/tests/ui/async-await/issue-70818.rs
@@ -4,6 +4,7 @@ use std::future::Future;
 fn foo<T: Send, U>(ty: T, ty1: U) -> impl Future<Output = (T, U)> + Send {
     //~^ ERROR future cannot be sent between threads safely
     async { (ty, ty1) }
+    //~^ ERROR future cannot be sent between threads safely
 }
 
 fn main() {}
diff --git a/tests/ui/async-await/issue-70818.stderr b/tests/ui/async-await/issue-70818.stderr
index 8de6a825042..07fd20cdd77 100644
--- a/tests/ui/async-await/issue-70818.stderr
+++ b/tests/ui/async-await/issue-70818.stderr
@@ -1,4 +1,25 @@
 error: future cannot be sent between threads safely
+  --> $DIR/issue-70818.rs:6:5
+   |
+LL |     async { (ty, ty1) }
+   |     ^^^^^^^^^^^^^^^^^^^ future created by async block is not `Send`
+   |
+note: captured value is not `Send`
+  --> $DIR/issue-70818.rs:6:18
+   |
+LL |     async { (ty, ty1) }
+   |                  ^^^ has type `U` which is not `Send`
+note: required by a bound in an opaque type
+  --> $DIR/issue-70818.rs:4:69
+   |
+LL | fn foo<T: Send, U>(ty: T, ty1: U) -> impl Future<Output = (T, U)> + Send {
+   |                                                                     ^^^^
+help: consider restricting type parameter `U` with trait `Send`
+   |
+LL | fn foo<T: Send, U: std::marker::Send>(ty: T, ty1: U) -> impl Future<Output = (T, U)> + Send {
+   |                  +++++++++++++++++++
+
+error: future cannot be sent between threads safely
   --> $DIR/issue-70818.rs:4:38
    |
 LL | fn foo<T: Send, U>(ty: T, ty1: U) -> impl Future<Output = (T, U)> + Send {
@@ -14,5 +35,5 @@ help: consider restricting type parameter `U` with trait `Send`
 LL | fn foo<T: Send, U: std::marker::Send>(ty: T, ty1: U) -> impl Future<Output = (T, U)> + Send {
    |                  +++++++++++++++++++
 
-error: aborting due to 1 previous error
+error: aborting due to 2 previous errors
 
diff --git a/tests/ui/async-await/issue-86507.stderr b/tests/ui/async-await/issue-86507.stderr
index 6385a8c975e..c71801dcfc8 100644
--- a/tests/ui/async-await/issue-86507.stderr
+++ b/tests/ui/async-await/issue-86507.stderr
@@ -13,7 +13,7 @@ note: captured value is not `Send` because `&` references cannot be sent unless
    |
 LL |                     let x = x;
    |                             ^ has type `&T` which is not `Send`, because `T` is not `Sync`
-   = note: required for the cast from `Pin<Box<{async block@$DIR/issue-86507.rs:18:17: 18:27}>>` to `Pin<Box<(dyn Future<Output = ()> + Send + 'async_trait)>>`
+   = note: required for the cast from `Pin<Box<{async block@$DIR/issue-86507.rs:18:17: 18:27}>>` to `Pin<Box<dyn Future<Output = ()> + Send>>`
 help: consider further restricting type parameter `T` with trait `Sync`
    |
 LL |     fn bar<'me, 'async_trait, T: Send + std::marker::Sync>(x: &'me T)
diff --git a/tests/ui/coroutine/clone-impl-async.rs b/tests/ui/coroutine/clone-impl-async.rs
index 2794b167aa2..4e2b26d0295 100644
--- a/tests/ui/coroutine/clone-impl-async.rs
+++ b/tests/ui/coroutine/clone-impl-async.rs
@@ -9,7 +9,7 @@ use std::future::ready;
 
 struct NonClone;
 
-fn main() {
+fn local() {
     let inner_non_clone = async {
         let non_clone = NonClone;
         let () = ready(()).await;
@@ -34,7 +34,9 @@ fn main() {
     //~^ ERROR : Copy` is not satisfied
     check_clone(&maybe_copy_clone);
     //~^ ERROR : Clone` is not satisfied
+}
 
+fn non_local() {
     let inner_non_clone_fn = the_inner_non_clone_fn();
     check_copy(&inner_non_clone_fn);
     //~^ ERROR : Copy` is not satisfied
@@ -69,3 +71,5 @@ async fn the_maybe_copy_clone_fn() {}
 
 fn check_copy<T: Copy>(_x: &T) {}
 fn check_clone<T: Clone>(_x: &T) {}
+
+fn main() {}
diff --git a/tests/ui/coroutine/clone-impl-async.stderr b/tests/ui/coroutine/clone-impl-async.stderr
index 62bcce2fbcb..319a5ed3d8d 100644
--- a/tests/ui/coroutine/clone-impl-async.stderr
+++ b/tests/ui/coroutine/clone-impl-async.stderr
@@ -1,167 +1,155 @@
-error[E0277]: the trait bound `{async block@$DIR/clone-impl-async.rs:13:27: 13:32}: Copy` is not satisfied
-  --> $DIR/clone-impl-async.rs:18:16
+error[E0277]: the trait bound `impl Future<Output = ()>: Copy` is not satisfied
+  --> $DIR/clone-impl-async.rs:41:16
    |
-LL |     check_copy(&inner_non_clone);
-   |     ---------- ^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `{async block@$DIR/clone-impl-async.rs:13:27: 13:32}`
+LL |     check_copy(&inner_non_clone_fn);
+   |     ---------- ^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `impl Future<Output = ()>`
    |     |
    |     required by a bound introduced by this call
    |
 note: required by a bound in `check_copy`
-  --> $DIR/clone-impl-async.rs:70:18
+  --> $DIR/clone-impl-async.rs:72:18
    |
 LL | fn check_copy<T: Copy>(_x: &T) {}
    |                  ^^^^ required by this bound in `check_copy`
 
-error[E0277]: the trait bound `{async block@$DIR/clone-impl-async.rs:13:27: 13:32}: Clone` is not satisfied
-  --> $DIR/clone-impl-async.rs:20:17
+error[E0277]: the trait bound `impl Future<Output = ()>: Clone` is not satisfied
+  --> $DIR/clone-impl-async.rs:43:17
    |
-LL |     check_clone(&inner_non_clone);
-   |     ----------- ^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `{async block@$DIR/clone-impl-async.rs:13:27: 13:32}`
+LL |     check_clone(&inner_non_clone_fn);
+   |     ----------- ^^^^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `impl Future<Output = ()>`
    |     |
    |     required by a bound introduced by this call
    |
 note: required by a bound in `check_clone`
-  --> $DIR/clone-impl-async.rs:71:19
+  --> $DIR/clone-impl-async.rs:73:19
    |
 LL | fn check_clone<T: Clone>(_x: &T) {}
    |                   ^^^^^ required by this bound in `check_clone`
 
-error[E0277]: the trait bound `{async block@$DIR/clone-impl-async.rs:24:27: 24:37}: Copy` is not satisfied
-  --> $DIR/clone-impl-async.rs:27:16
+error[E0277]: the trait bound `impl Future<Output = ()>: Copy` is not satisfied
+  --> $DIR/clone-impl-async.rs:47:16
    |
-LL |     check_copy(&outer_non_clone);
-   |     ---------- ^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `{async block@$DIR/clone-impl-async.rs:24:27: 24:37}`
+LL |     check_copy(&outer_non_clone_fn);
+   |     ---------- ^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `impl Future<Output = ()>`
    |     |
    |     required by a bound introduced by this call
    |
 note: required by a bound in `check_copy`
-  --> $DIR/clone-impl-async.rs:70:18
+  --> $DIR/clone-impl-async.rs:72:18
    |
 LL | fn check_copy<T: Copy>(_x: &T) {}
    |                  ^^^^ required by this bound in `check_copy`
 
-error[E0277]: the trait bound `{async block@$DIR/clone-impl-async.rs:24:27: 24:37}: Clone` is not satisfied
-  --> $DIR/clone-impl-async.rs:29:17
+error[E0277]: the trait bound `impl Future<Output = ()>: Clone` is not satisfied
+  --> $DIR/clone-impl-async.rs:49:17
    |
-LL |     check_clone(&outer_non_clone);
-   |     ----------- ^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `{async block@$DIR/clone-impl-async.rs:24:27: 24:37}`
+LL |     check_clone(&outer_non_clone_fn);
+   |     ----------- ^^^^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `impl Future<Output = ()>`
    |     |
    |     required by a bound introduced by this call
    |
 note: required by a bound in `check_clone`
-  --> $DIR/clone-impl-async.rs:71:19
+  --> $DIR/clone-impl-async.rs:73:19
    |
 LL | fn check_clone<T: Clone>(_x: &T) {}
    |                   ^^^^^ required by this bound in `check_clone`
 
-error[E0277]: the trait bound `{async block@$DIR/clone-impl-async.rs:32:28: 32:38}: Copy` is not satisfied
-  --> $DIR/clone-impl-async.rs:33:16
+error[E0277]: the trait bound `impl Future<Output = ()>: Copy` is not satisfied
+  --> $DIR/clone-impl-async.rs:53:16
    |
-LL |     check_copy(&maybe_copy_clone);
-   |     ---------- ^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `{async block@$DIR/clone-impl-async.rs:32:28: 32:38}`
+LL |     check_copy(&maybe_copy_clone_fn);
+   |     ---------- ^^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `impl Future<Output = ()>`
    |     |
    |     required by a bound introduced by this call
    |
 note: required by a bound in `check_copy`
-  --> $DIR/clone-impl-async.rs:70:18
+  --> $DIR/clone-impl-async.rs:72:18
    |
 LL | fn check_copy<T: Copy>(_x: &T) {}
    |                  ^^^^ required by this bound in `check_copy`
 
-error[E0277]: the trait bound `{async block@$DIR/clone-impl-async.rs:32:28: 32:38}: Clone` is not satisfied
-  --> $DIR/clone-impl-async.rs:35:17
+error[E0277]: the trait bound `impl Future<Output = ()>: Clone` is not satisfied
+  --> $DIR/clone-impl-async.rs:55:17
    |
-LL |     check_clone(&maybe_copy_clone);
-   |     ----------- ^^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `{async block@$DIR/clone-impl-async.rs:32:28: 32:38}`
+LL |     check_clone(&maybe_copy_clone_fn);
+   |     ----------- ^^^^^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `impl Future<Output = ()>`
    |     |
    |     required by a bound introduced by this call
    |
 note: required by a bound in `check_clone`
-  --> $DIR/clone-impl-async.rs:71:19
+  --> $DIR/clone-impl-async.rs:73:19
    |
 LL | fn check_clone<T: Clone>(_x: &T) {}
    |                   ^^^^^ required by this bound in `check_clone`
 
-error[E0277]: the trait bound `impl Future<Output = ()>: Copy` is not satisfied
-  --> $DIR/clone-impl-async.rs:39:16
+error[E0277]: the trait bound `{async block@$DIR/clone-impl-async.rs:13:27: 13:32}: Copy` is not satisfied
+  --> $DIR/clone-impl-async.rs:18:5
    |
-LL |     check_copy(&inner_non_clone_fn);
-   |     ---------- ^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `impl Future<Output = ()>`
-   |     |
-   |     required by a bound introduced by this call
+LL |     check_copy(&inner_non_clone);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `{async block@$DIR/clone-impl-async.rs:13:27: 13:32}`
    |
 note: required by a bound in `check_copy`
-  --> $DIR/clone-impl-async.rs:70:18
+  --> $DIR/clone-impl-async.rs:72:18
    |
 LL | fn check_copy<T: Copy>(_x: &T) {}
    |                  ^^^^ required by this bound in `check_copy`
 
-error[E0277]: the trait bound `impl Future<Output = ()>: Clone` is not satisfied
-  --> $DIR/clone-impl-async.rs:41:17
+error[E0277]: the trait bound `{async block@$DIR/clone-impl-async.rs:13:27: 13:32}: Clone` is not satisfied
+  --> $DIR/clone-impl-async.rs:20:5
    |
-LL |     check_clone(&inner_non_clone_fn);
-   |     ----------- ^^^^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `impl Future<Output = ()>`
-   |     |
-   |     required by a bound introduced by this call
+LL |     check_clone(&inner_non_clone);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `{async block@$DIR/clone-impl-async.rs:13:27: 13:32}`
    |
 note: required by a bound in `check_clone`
-  --> $DIR/clone-impl-async.rs:71:19
+  --> $DIR/clone-impl-async.rs:73:19
    |
 LL | fn check_clone<T: Clone>(_x: &T) {}
    |                   ^^^^^ required by this bound in `check_clone`
 
-error[E0277]: the trait bound `impl Future<Output = ()>: Copy` is not satisfied
-  --> $DIR/clone-impl-async.rs:45:16
+error[E0277]: the trait bound `{async block@$DIR/clone-impl-async.rs:24:27: 24:37}: Copy` is not satisfied
+  --> $DIR/clone-impl-async.rs:27:5
    |
-LL |     check_copy(&outer_non_clone_fn);
-   |     ---------- ^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `impl Future<Output = ()>`
-   |     |
-   |     required by a bound introduced by this call
+LL |     check_copy(&outer_non_clone);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `{async block@$DIR/clone-impl-async.rs:24:27: 24:37}`
    |
 note: required by a bound in `check_copy`
-  --> $DIR/clone-impl-async.rs:70:18
+  --> $DIR/clone-impl-async.rs:72:18
    |
 LL | fn check_copy<T: Copy>(_x: &T) {}
    |                  ^^^^ required by this bound in `check_copy`
 
-error[E0277]: the trait bound `impl Future<Output = ()>: Clone` is not satisfied
-  --> $DIR/clone-impl-async.rs:47:17
+error[E0277]: the trait bound `{async block@$DIR/clone-impl-async.rs:24:27: 24:37}: Clone` is not satisfied
+  --> $DIR/clone-impl-async.rs:29:5
    |
-LL |     check_clone(&outer_non_clone_fn);
-   |     ----------- ^^^^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `impl Future<Output = ()>`
-   |     |
-   |     required by a bound introduced by this call
+LL |     check_clone(&outer_non_clone);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `{async block@$DIR/clone-impl-async.rs:24:27: 24:37}`
    |
 note: required by a bound in `check_clone`
-  --> $DIR/clone-impl-async.rs:71:19
+  --> $DIR/clone-impl-async.rs:73:19
    |
 LL | fn check_clone<T: Clone>(_x: &T) {}
    |                   ^^^^^ required by this bound in `check_clone`
 
-error[E0277]: the trait bound `impl Future<Output = ()>: Copy` is not satisfied
-  --> $DIR/clone-impl-async.rs:51:16
+error[E0277]: the trait bound `{async block@$DIR/clone-impl-async.rs:32:28: 32:38}: Copy` is not satisfied
+  --> $DIR/clone-impl-async.rs:33:5
    |
-LL |     check_copy(&maybe_copy_clone_fn);
-   |     ---------- ^^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `impl Future<Output = ()>`
-   |     |
-   |     required by a bound introduced by this call
+LL |     check_copy(&maybe_copy_clone);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `{async block@$DIR/clone-impl-async.rs:32:28: 32:38}`
    |
 note: required by a bound in `check_copy`
-  --> $DIR/clone-impl-async.rs:70:18
+  --> $DIR/clone-impl-async.rs:72:18
    |
 LL | fn check_copy<T: Copy>(_x: &T) {}
    |                  ^^^^ required by this bound in `check_copy`
 
-error[E0277]: the trait bound `impl Future<Output = ()>: Clone` is not satisfied
-  --> $DIR/clone-impl-async.rs:53:17
+error[E0277]: the trait bound `{async block@$DIR/clone-impl-async.rs:32:28: 32:38}: Clone` is not satisfied
+  --> $DIR/clone-impl-async.rs:35:5
    |
-LL |     check_clone(&maybe_copy_clone_fn);
-   |     ----------- ^^^^^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `impl Future<Output = ()>`
-   |     |
-   |     required by a bound introduced by this call
+LL |     check_clone(&maybe_copy_clone);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `{async block@$DIR/clone-impl-async.rs:32:28: 32:38}`
    |
 note: required by a bound in `check_clone`
-  --> $DIR/clone-impl-async.rs:71:19
+  --> $DIR/clone-impl-async.rs:73:19
    |
 LL | fn check_clone<T: Clone>(_x: &T) {}
    |                   ^^^^^ required by this bound in `check_clone`
diff --git a/tests/ui/coroutine/clone-impl-static.stderr b/tests/ui/coroutine/clone-impl-static.stderr
index 9fb71fd5fd0..4df6b9759c3 100644
--- a/tests/ui/coroutine/clone-impl-static.stderr
+++ b/tests/ui/coroutine/clone-impl-static.stderr
@@ -1,10 +1,8 @@
 error[E0277]: the trait bound `{static coroutine@$DIR/clone-impl-static.rs:11:5: 11:19}: Copy` is not satisfied
-  --> $DIR/clone-impl-static.rs:14:16
+  --> $DIR/clone-impl-static.rs:14:5
    |
 LL |     check_copy(&generator);
-   |     ---------- ^^^^^^^^^^ the trait `Copy` is not implemented for `{static coroutine@$DIR/clone-impl-static.rs:11:5: 11:19}`
-   |     |
-   |     required by a bound introduced by this call
+   |     ^^^^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `{static coroutine@$DIR/clone-impl-static.rs:11:5: 11:19}`
    |
 note: required by a bound in `check_copy`
   --> $DIR/clone-impl-static.rs:20:18
@@ -13,12 +11,10 @@ LL | fn check_copy<T: Copy>(_x: &T) {}
    |                  ^^^^ required by this bound in `check_copy`
 
 error[E0277]: the trait bound `{static coroutine@$DIR/clone-impl-static.rs:11:5: 11:19}: Clone` is not satisfied
-  --> $DIR/clone-impl-static.rs:16:17
+  --> $DIR/clone-impl-static.rs:16:5
    |
 LL |     check_clone(&generator);
-   |     ----------- ^^^^^^^^^^ the trait `Clone` is not implemented for `{static coroutine@$DIR/clone-impl-static.rs:11:5: 11:19}`
-   |     |
-   |     required by a bound introduced by this call
+   |     ^^^^^^^^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `{static coroutine@$DIR/clone-impl-static.rs:11:5: 11:19}`
    |
 note: required by a bound in `check_clone`
   --> $DIR/clone-impl-static.rs:21:19
diff --git a/tests/ui/coroutine/clone-impl.rs b/tests/ui/coroutine/clone-impl.rs
index e528f031d52..9e04e256fc1 100644
--- a/tests/ui/coroutine/clone-impl.rs
+++ b/tests/ui/coroutine/clone-impl.rs
@@ -42,6 +42,7 @@ fn test3_upvars() {
     let clonable_0: Vec<u32> = Vec::new();
     let gen_clone_0 = #[coroutine]
     move || {
+        yield;
         drop(clonable_0);
     };
     check_copy(&gen_clone_0);
diff --git a/tests/ui/coroutine/clone-impl.stderr b/tests/ui/coroutine/clone-impl.stderr
index 714e5aa3d9e..f316902a42d 100644
--- a/tests/ui/coroutine/clone-impl.stderr
+++ b/tests/ui/coroutine/clone-impl.stderr
@@ -1,59 +1,81 @@
 error[E0277]: the trait bound `Vec<u32>: Copy` is not satisfied in `{coroutine@$DIR/clone-impl.rs:44:5: 44:12}`
-  --> $DIR/clone-impl.rs:47:16
+  --> $DIR/clone-impl.rs:48:5
    |
 LL |     move || {
    |     ------- within this `{coroutine@$DIR/clone-impl.rs:44:5: 44:12}`
 ...
 LL |     check_copy(&gen_clone_0);
-   |                ^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:44:5: 44:12}`, the trait `Copy` is not implemented for `Vec<u32>`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:44:5: 44:12}`, the trait `Copy` is not implemented for `Vec<u32>`
    |
 note: captured value does not implement `Copy`
-  --> $DIR/clone-impl.rs:45:14
+  --> $DIR/clone-impl.rs:46:14
    |
 LL |         drop(clonable_0);
    |              ^^^^^^^^^^ has type `Vec<u32>` which does not implement `Copy`
 note: required by a bound in `check_copy`
-  --> $DIR/clone-impl.rs:91:18
+  --> $DIR/clone-impl.rs:92:18
    |
 LL | fn check_copy<T: Copy>(_x: &T) {}
    |                  ^^^^ required by this bound in `check_copy`
 
-error[E0277]: the trait bound `Vec<u32>: Copy` is not satisfied in `{coroutine@$DIR/clone-impl.rs:67:5: 67:12}`
-  --> $DIR/clone-impl.rs:73:16
+error[E0277]: the trait bound `Vec<char>: Copy` is not satisfied in `{coroutine@$DIR/clone-impl.rs:55:5: 55:12}`
+  --> $DIR/clone-impl.rs:60:5
    |
 LL |     move || {
-   |     ------- within this `{coroutine@$DIR/clone-impl.rs:67:5: 67:12}`
+   |     ------- within this `{coroutine@$DIR/clone-impl.rs:55:5: 55:12}`
 ...
 LL |     check_copy(&gen_clone_1);
-   |                ^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:67:5: 67:12}`, the trait `Copy` is not implemented for `Vec<u32>`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:55:5: 55:12}`, the trait `Copy` is not implemented for `Vec<char>`
+   |
+note: coroutine does not implement `Copy` as this value is used across a yield
+  --> $DIR/clone-impl.rs:57:9
+   |
+LL |         let v = vec!['a'];
+   |             - has type `Vec<char>` which does not implement `Copy`
+LL |         yield;
+   |         ^^^^^ yield occurs here, with `v` maybe used later
+note: required by a bound in `check_copy`
+  --> $DIR/clone-impl.rs:92:18
+   |
+LL | fn check_copy<T: Copy>(_x: &T) {}
+   |                  ^^^^ required by this bound in `check_copy`
+
+error[E0277]: the trait bound `Vec<u32>: Copy` is not satisfied in `{coroutine@$DIR/clone-impl.rs:68:5: 68:12}`
+  --> $DIR/clone-impl.rs:74:5
+   |
+LL |     move || {
+   |     ------- within this `{coroutine@$DIR/clone-impl.rs:68:5: 68:12}`
+...
+LL |     check_copy(&gen_clone_1);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:68:5: 68:12}`, the trait `Copy` is not implemented for `Vec<u32>`
    |
 note: captured value does not implement `Copy`
-  --> $DIR/clone-impl.rs:71:14
+  --> $DIR/clone-impl.rs:72:14
    |
 LL |         drop(clonable_1);
    |              ^^^^^^^^^^ has type `Vec<u32>` which does not implement `Copy`
 note: required by a bound in `check_copy`
-  --> $DIR/clone-impl.rs:91:18
+  --> $DIR/clone-impl.rs:92:18
    |
 LL | fn check_copy<T: Copy>(_x: &T) {}
    |                  ^^^^ required by this bound in `check_copy`
 
-error[E0277]: the trait bound `NonClone: Copy` is not satisfied in `{coroutine@$DIR/clone-impl.rs:81:5: 81:12}`
-  --> $DIR/clone-impl.rs:85:16
+error[E0277]: the trait bound `NonClone: Copy` is not satisfied in `{coroutine@$DIR/clone-impl.rs:82:5: 82:12}`
+  --> $DIR/clone-impl.rs:86:5
    |
 LL |     move || {
-   |     ------- within this `{coroutine@$DIR/clone-impl.rs:81:5: 81:12}`
+   |     ------- within this `{coroutine@$DIR/clone-impl.rs:82:5: 82:12}`
 ...
 LL |     check_copy(&gen_non_clone);
-   |                ^^^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:81:5: 81:12}`, the trait `Copy` is not implemented for `NonClone`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:82:5: 82:12}`, the trait `Copy` is not implemented for `NonClone`
    |
 note: captured value does not implement `Copy`
-  --> $DIR/clone-impl.rs:83:14
+  --> $DIR/clone-impl.rs:84:14
    |
 LL |         drop(non_clonable);
    |              ^^^^^^^^^^^^ has type `NonClone` which does not implement `Copy`
 note: required by a bound in `check_copy`
-  --> $DIR/clone-impl.rs:91:18
+  --> $DIR/clone-impl.rs:92:18
    |
 LL | fn check_copy<T: Copy>(_x: &T) {}
    |                  ^^^^ required by this bound in `check_copy`
@@ -63,22 +85,22 @@ LL + #[derive(Copy)]
 LL | struct NonClone;
    |
 
-error[E0277]: the trait bound `NonClone: Clone` is not satisfied in `{coroutine@$DIR/clone-impl.rs:81:5: 81:12}`
-  --> $DIR/clone-impl.rs:87:17
+error[E0277]: the trait bound `NonClone: Clone` is not satisfied in `{coroutine@$DIR/clone-impl.rs:82:5: 82:12}`
+  --> $DIR/clone-impl.rs:88:5
    |
 LL |     move || {
-   |     ------- within this `{coroutine@$DIR/clone-impl.rs:81:5: 81:12}`
+   |     ------- within this `{coroutine@$DIR/clone-impl.rs:82:5: 82:12}`
 ...
 LL |     check_clone(&gen_non_clone);
-   |                 ^^^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:81:5: 81:12}`, the trait `Clone` is not implemented for `NonClone`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:82:5: 82:12}`, the trait `Clone` is not implemented for `NonClone`
    |
 note: captured value does not implement `Clone`
-  --> $DIR/clone-impl.rs:83:14
+  --> $DIR/clone-impl.rs:84:14
    |
 LL |         drop(non_clonable);
    |              ^^^^^^^^^^^^ has type `NonClone` which does not implement `Clone`
 note: required by a bound in `check_clone`
-  --> $DIR/clone-impl.rs:92:19
+  --> $DIR/clone-impl.rs:93:19
    |
 LL | fn check_clone<T: Clone>(_x: &T) {}
    |                   ^^^^^ required by this bound in `check_clone`
@@ -88,28 +110,6 @@ LL + #[derive(Clone)]
 LL | struct NonClone;
    |
 
-error[E0277]: the trait bound `Vec<char>: Copy` is not satisfied in `{coroutine@$DIR/clone-impl.rs:54:5: 54:12}`
-  --> $DIR/clone-impl.rs:59:5
-   |
-LL |     move || {
-   |     ------- within this `{coroutine@$DIR/clone-impl.rs:54:5: 54:12}`
-...
-LL |     check_copy(&gen_clone_1);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:54:5: 54:12}`, the trait `Copy` is not implemented for `Vec<char>`
-   |
-note: coroutine does not implement `Copy` as this value is used across a yield
-  --> $DIR/clone-impl.rs:56:9
-   |
-LL |         let v = vec!['a'];
-   |             - has type `Vec<char>` which does not implement `Copy`
-LL |         yield;
-   |         ^^^^^ yield occurs here, with `v` maybe used later
-note: required by a bound in `check_copy`
-  --> $DIR/clone-impl.rs:91:18
-   |
-LL | fn check_copy<T: Copy>(_x: &T) {}
-   |                  ^^^^ required by this bound in `check_copy`
-
 error: aborting due to 5 previous errors
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/coroutine/print/coroutine-print-verbose-2.stderr b/tests/ui/coroutine/print/coroutine-print-verbose-2.stderr
index 8877d45ddda..11b78e3bcf8 100644
--- a/tests/ui/coroutine/print/coroutine-print-verbose-2.stderr
+++ b/tests/ui/coroutine/print/coroutine-print-verbose-2.stderr
@@ -9,7 +9,7 @@ LL | |         drop(a);
 LL | |     });
    | |______^ coroutine is not `Sync`
    |
-   = help: within `{main::{closure#0} upvar_tys=() resume_ty=() yield_ty=() return_ty=() witness={main::{closure#0}}}`, the trait `Sync` is not implemented for `NotSync`
+   = help: within `{main::{closure#0} upvar_tys=() resume_ty=() yield_ty=() return_ty=()}`, the trait `Sync` is not implemented for `NotSync`
 note: coroutine is not `Sync` as this value is used across a yield
   --> $DIR/coroutine-print-verbose-2.rs:20:9
    |
@@ -34,7 +34,7 @@ LL | |         drop(a);
 LL | |     });
    | |______^ coroutine is not `Send`
    |
-   = help: within `{main::{closure#1} upvar_tys=() resume_ty=() yield_ty=() return_ty=() witness={main::{closure#1}}}`, the trait `Send` is not implemented for `NotSend`
+   = help: within `{main::{closure#1} upvar_tys=() resume_ty=() yield_ty=() return_ty=()}`, the trait `Send` is not implemented for `NotSend`
 note: coroutine is not `Send` as this value is used across a yield
   --> $DIR/coroutine-print-verbose-2.rs:27:9
    |
diff --git a/tests/ui/coroutine/print/coroutine-print-verbose-3.stderr b/tests/ui/coroutine/print/coroutine-print-verbose-3.stderr
index 4a1e5b078a8..135e8175793 100644
--- a/tests/ui/coroutine/print/coroutine-print-verbose-3.stderr
+++ b/tests/ui/coroutine/print/coroutine-print-verbose-3.stderr
@@ -11,7 +11,7 @@ LL | |     };
    | |_____^ expected `()`, found coroutine
    |
    = note: expected unit type `()`
-              found coroutine `{main::{closure#0} upvar_tys=?4t resume_ty=() yield_ty=i32 return_ty=&'?1 str witness={main::{closure#0}}}`
+              found coroutine `{main::{closure#0} upvar_tys=?4t resume_ty=() yield_ty=i32 return_ty=&'?1 str}`
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/coroutine/ref-upvar-not-send.stderr b/tests/ui/coroutine/ref-upvar-not-send.stderr
index 892b5d261c2..3a5e8ec4dab 100644
--- a/tests/ui/coroutine/ref-upvar-not-send.stderr
+++ b/tests/ui/coroutine/ref-upvar-not-send.stderr
@@ -1,14 +1,13 @@
 error: coroutine cannot be sent between threads safely
-  --> $DIR/ref-upvar-not-send.rs:15:30
+  --> $DIR/ref-upvar-not-send.rs:15:5
    |
-LL |       assert_send(#[coroutine] move || {
-   |  ______________________________^
+LL | /     assert_send(#[coroutine] move || {
 LL | |
 LL | |
 LL | |         yield;
 LL | |         let _x = x;
 LL | |     });
-   | |_____^ coroutine is not `Send`
+   | |______^ coroutine is not `Send`
    |
    = help: the trait `Sync` is not implemented for `*mut ()`
 note: captured value is not `Send` because `&` references cannot be sent unless their referent is `Sync`
@@ -23,16 +22,15 @@ LL | fn assert_send<T: Send>(_: T) {}
    |                   ^^^^ required by this bound in `assert_send`
 
 error: coroutine cannot be sent between threads safely
-  --> $DIR/ref-upvar-not-send.rs:23:30
+  --> $DIR/ref-upvar-not-send.rs:23:5
    |
-LL |       assert_send(#[coroutine] move || {
-   |  ______________________________^
+LL | /     assert_send(#[coroutine] move || {
 LL | |
 LL | |
 LL | |         yield;
 LL | |         let _y = y;
 LL | |     });
-   | |_____^ coroutine is not `Send`
+   | |______^ coroutine is not `Send`
    |
    = help: within `{coroutine@$DIR/ref-upvar-not-send.rs:23:30: 23:37}`, the trait `Send` is not implemented for `*mut ()`
 note: captured value is not `Send` because `&mut` references cannot be sent unless their referent is `Send`
diff --git a/tests/ui/impl-trait/issues/issue-55872-2.rs b/tests/ui/impl-trait/issues/issue-55872-2.rs
index a3b2225126a..aea00dd9e3d 100644
--- a/tests/ui/impl-trait/issues/issue-55872-2.rs
+++ b/tests/ui/impl-trait/issues/issue-55872-2.rs
@@ -12,7 +12,6 @@ impl<S> Bar for S {
     type E = impl std::marker::Send;
     fn foo<T>() -> Self::E {
         //~^ ERROR type parameter `T` is part of concrete type but not used in parameter list for the `impl Trait` type alias
-        //~| ERROR type parameter `T` is part of concrete type but not used in parameter list for the `impl Trait` type alias
         async {}
     }
 }
diff --git a/tests/ui/impl-trait/issues/issue-55872-2.stderr b/tests/ui/impl-trait/issues/issue-55872-2.stderr
index 51a7dd00ade..91c2ecdc8a4 100644
--- a/tests/ui/impl-trait/issues/issue-55872-2.stderr
+++ b/tests/ui/impl-trait/issues/issue-55872-2.stderr
@@ -4,13 +4,5 @@ error: type parameter `T` is part of concrete type but not used in parameter lis
 LL |     fn foo<T>() -> Self::E {
    |                    ^^^^^^^
 
-error: type parameter `T` is part of concrete type but not used in parameter list for the `impl Trait` type alias
-  --> $DIR/issue-55872-2.rs:13:20
-   |
-LL |     fn foo<T>() -> Self::E {
-   |                    ^^^^^^^
-   |
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-error: aborting due to 2 previous errors
+error: aborting due to 1 previous error
 
diff --git a/tests/ui/impl-trait/issues/issue-55872-3.rs b/tests/ui/impl-trait/issues/issue-55872-3.rs
index 763b4b9fd32..698e7f36234 100644
--- a/tests/ui/impl-trait/issues/issue-55872-3.rs
+++ b/tests/ui/impl-trait/issues/issue-55872-3.rs
@@ -14,7 +14,6 @@ impl<S> Bar for S {
     fn foo<T>() -> Self::E {
         //~^ ERROR : Copy` is not satisfied [E0277]
         //~| ERROR type parameter `T` is part of concrete type
-        //~| ERROR type parameter `T` is part of concrete type
         async {}
     }
 }
diff --git a/tests/ui/impl-trait/issues/issue-55872-3.stderr b/tests/ui/impl-trait/issues/issue-55872-3.stderr
index ce2dd7f02b4..5124c46baeb 100644
--- a/tests/ui/impl-trait/issues/issue-55872-3.stderr
+++ b/tests/ui/impl-trait/issues/issue-55872-3.stderr
@@ -1,26 +1,15 @@
-error[E0277]: the trait bound `{async block@$DIR/issue-55872-3.rs:18:9: 18:14}: Copy` is not satisfied
-  --> $DIR/issue-55872-3.rs:14:20
-   |
-LL |     fn foo<T>() -> Self::E {
-   |                    ^^^^^^^ the trait `Copy` is not implemented for `{async block@$DIR/issue-55872-3.rs:18:9: 18:14}`
-...
-LL |         async {}
-   |         -------- return type was inferred to be `{async block@$DIR/issue-55872-3.rs:18:9: 18:14}` here
-
 error: type parameter `T` is part of concrete type but not used in parameter list for the `impl Trait` type alias
   --> $DIR/issue-55872-3.rs:14:20
    |
 LL |     fn foo<T>() -> Self::E {
    |                    ^^^^^^^
 
-error: type parameter `T` is part of concrete type but not used in parameter list for the `impl Trait` type alias
+error[E0277]: the trait bound `{async block@$DIR/issue-55872-3.rs:17:9: 17:14}: Copy` is not satisfied
   --> $DIR/issue-55872-3.rs:14:20
    |
 LL |     fn foo<T>() -> Self::E {
-   |                    ^^^^^^^
-   |
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+   |                    ^^^^^^^ the trait `Copy` is not implemented for `{async block@$DIR/issue-55872-3.rs:17:9: 17:14}`
 
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0277`.