Merging upstream version 1.76.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

28 files changed, 206 insertions, 29 deletions

diff --git a/tests/ui/traits/trait-upcasting/alias-where-clause-isnt-supertrait.stderr b/tests/ui/traits/trait-upcasting/alias-where-clause-isnt-supertrait.stderr
index 5574a0320..99c82b88d 100644
--- a/tests/ui/traits/trait-upcasting/alias-where-clause-isnt-supertrait.stderr
+++ b/tests/ui/traits/trait-upcasting/alias-where-clause-isnt-supertrait.stderr
@@ -9,6 +9,6 @@ LL |     x
    = note: expected reference `&dyn B`
               found reference `&dyn C`
 
-error: aborting due to previous error
+error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/traits/trait-upcasting/cyclic-trait-resolution.stderr b/tests/ui/traits/trait-upcasting/cyclic-trait-resolution.stderr
index 62c732fb1..85c05bd05 100644
--- a/tests/ui/traits/trait-upcasting/cyclic-trait-resolution.stderr
+++ b/tests/ui/traits/trait-upcasting/cyclic-trait-resolution.stderr
@@ -12,6 +12,6 @@ LL | trait A: B + A {}
    | ^^^^^^^^^^^^^^^^^
    = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
-error: aborting due to previous error
+error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0391`.
diff --git a/tests/ui/traits/trait-upcasting/deref-upcast-behavioral-change.rs b/tests/ui/traits/trait-upcasting/deref-upcast-behavioral-change.rs
new file mode 100644
index 000000000..e4784fa41
--- /dev/null
+++ b/tests/ui/traits/trait-upcasting/deref-upcast-behavioral-change.rs
@@ -0,0 +1,35 @@
+#![deny(deref_into_dyn_supertrait)]
+use std::ops::Deref;
+
+trait Bar<T> {}
+impl<T, U> Bar<U> for T {}
+
+trait Foo: Bar<i32> {
+    fn as_dyn_bar_u32<'a>(&self) -> &(dyn Bar<u32> + 'a);
+}
+
+impl Foo for () {
+    fn as_dyn_bar_u32<'a>(&self) -> &(dyn Bar<u32> + 'a) {
+        self
+    }
+}
+
+impl<'a> Deref for dyn Foo + 'a {
+    //~^ ERROR this `Deref` implementation is covered by an implicit supertrait coercion
+    //~| WARN this will change its meaning in a future release!
+    type Target = dyn Bar<u32> + 'a;
+
+    fn deref(&self) -> &Self::Target {
+        self.as_dyn_bar_u32()
+    }
+}
+
+fn take_dyn<T>(x: &dyn Bar<T>) -> T {
+    todo!()
+}
+
+fn main() {
+    let x: &dyn Foo = &();
+    let y = take_dyn(x);
+    let z: u32 = y;
+}
diff --git a/tests/ui/traits/trait-upcasting/deref-upcast-behavioral-change.stderr b/tests/ui/traits/trait-upcasting/deref-upcast-behavioral-change.stderr
new file mode 100644
index 000000000..fa93e28c7
--- /dev/null
+++ b/tests/ui/traits/trait-upcasting/deref-upcast-behavioral-change.stderr
@@ -0,0 +1,19 @@
+error: this `Deref` implementation is covered by an implicit supertrait coercion
+  --> $DIR/deref-upcast-behavioral-change.rs:17:1
+   |
+LL | impl<'a> Deref for dyn Foo + 'a {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `dyn Foo` implements `Deref<Target = dyn Bar<u32>>` which conflicts with supertrait `Bar<i32>`
+...
+LL |     type Target = dyn Bar<u32> + 'a;
+   |     -------------------------------- target type is a supertrait of `dyn Foo`
+   |
+   = warning: this will change its meaning in a future release!
+   = note: for more information, see issue #89460 <https://github.com/rust-lang/rust/issues/89460>
+note: the lint level is defined here
+  --> $DIR/deref-upcast-behavioral-change.rs:1:9
+   |
+LL | #![deny(deref_into_dyn_supertrait)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/traits/trait-upcasting/fewer-associated.rs b/tests/ui/traits/trait-upcasting/fewer-associated.rs
index 8228eea26..58e72d9d7 100644
--- a/tests/ui/traits/trait-upcasting/fewer-associated.rs
+++ b/tests/ui/traits/trait-upcasting/fewer-associated.rs
@@ -1,7 +1,7 @@
 // check-pass
 // issue: 114035
 // revisions: current next
-//[next] compile-flags: -Ztrait-solver=next
+//[next] compile-flags: -Znext-solver
 
 #![feature(trait_upcasting)]
 
diff --git a/tests/ui/traits/trait-upcasting/illegal-upcast-from-impl.current.stderr b/tests/ui/traits/trait-upcasting/illegal-upcast-from-impl.current.stderr
index 59c9d5737..1538e2f3f 100644
--- a/tests/ui/traits/trait-upcasting/illegal-upcast-from-impl.current.stderr
+++ b/tests/ui/traits/trait-upcasting/illegal-upcast-from-impl.current.stderr
@@ -9,6 +9,6 @@ LL | fn illegal(x: &dyn Sub<Assoc = ()>) -> &dyn Super<Assoc = i32> { x }
    = note: expected reference `&dyn Super<Assoc = i32>`
               found reference `&dyn Sub<Assoc = ()>`
 
-error: aborting due to previous error
+error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/traits/trait-upcasting/illegal-upcast-from-impl.next.stderr b/tests/ui/traits/trait-upcasting/illegal-upcast-from-impl.next.stderr
index 59c9d5737..1538e2f3f 100644
--- a/tests/ui/traits/trait-upcasting/illegal-upcast-from-impl.next.stderr
+++ b/tests/ui/traits/trait-upcasting/illegal-upcast-from-impl.next.stderr
@@ -9,6 +9,6 @@ LL | fn illegal(x: &dyn Sub<Assoc = ()>) -> &dyn Super<Assoc = i32> { x }
    = note: expected reference `&dyn Super<Assoc = i32>`
               found reference `&dyn Sub<Assoc = ()>`
 
-error: aborting due to previous error
+error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/traits/trait-upcasting/illegal-upcast-from-impl.rs b/tests/ui/traits/trait-upcasting/illegal-upcast-from-impl.rs
index 774474281..ffed8beb4 100644
--- a/tests/ui/traits/trait-upcasting/illegal-upcast-from-impl.rs
+++ b/tests/ui/traits/trait-upcasting/illegal-upcast-from-impl.rs
@@ -1,5 +1,5 @@
 // revisions: current next
-//[next] compile-flags: -Ztrait-solver=next
+//[next] compile-flags: -Znext-solver
 
 #![feature(trait_upcasting)]
 
diff --git a/tests/ui/traits/trait-upcasting/inference-behavior-change-deref.rs b/tests/ui/traits/trait-upcasting/inference-behavior-change-deref.rs
new file mode 100644
index 000000000..79fb643ea
--- /dev/null
+++ b/tests/ui/traits/trait-upcasting/inference-behavior-change-deref.rs
@@ -0,0 +1,36 @@
+#![deny(deref_into_dyn_supertrait)]
+#![feature(trait_upcasting)] // remove this and the test compiles
+
+use std::ops::Deref;
+
+trait Bar<T> {}
+impl<T, U> Bar<U> for T {}
+
+trait Foo: Bar<i32> {
+    fn as_dyn_bar_u32<'a>(&self) -> &(dyn Bar<u32> + 'a);
+}
+
+impl Foo for () {
+    fn as_dyn_bar_u32<'a>(&self) -> &(dyn Bar<u32> + 'a) {
+        self
+    }
+}
+
+impl<'a> Deref for dyn Foo + 'a {
+    type Target = dyn Bar<u32> + 'a;
+
+    fn deref(&self) -> &Self::Target {
+        self.as_dyn_bar_u32()
+    }
+}
+
+fn take_dyn<T>(x: &dyn Bar<T>) -> T {
+    todo!()
+}
+
+fn main() {
+    let x: &dyn Foo = &();
+    let y = take_dyn(x);
+    let z: u32 = y;
+    //~^ ERROR mismatched types
+}
diff --git a/tests/ui/traits/trait-upcasting/inference-behavior-change-deref.stderr b/tests/ui/traits/trait-upcasting/inference-behavior-change-deref.stderr
new file mode 100644
index 000000000..6b6a26d15
--- /dev/null
+++ b/tests/ui/traits/trait-upcasting/inference-behavior-change-deref.stderr
@@ -0,0 +1,16 @@
+error[E0308]: mismatched types
+  --> $DIR/inference-behavior-change-deref.rs:34:18
+   |
+LL |     let z: u32 = y;
+   |            ---   ^ expected `u32`, found `i32`
+   |            |
+   |            expected due to this
+   |
+help: you can convert an `i32` to a `u32` and panic if the converted value doesn't fit
+   |
+LL |     let z: u32 = y.try_into().unwrap();
+   |                   ++++++++++++++++++++
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/traits/trait-upcasting/issue-11515.current.stderr b/tests/ui/traits/trait-upcasting/issue-11515.current.stderr
index 97d66cccb..da7ac4cc0 100644
--- a/tests/ui/traits/trait-upcasting/issue-11515.current.stderr
+++ b/tests/ui/traits/trait-upcasting/issue-11515.current.stderr
@@ -8,6 +8,6 @@ LL |     let test = Box::new(Test { func: closure });
    = help: add `#![feature(trait_upcasting)]` to the crate attributes to enable
    = note: required when coercing `Box<(dyn Fn() + 'static)>` into `Box<(dyn FnMut() + 'static)>`
 
-error: aborting due to previous error
+error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0658`.
diff --git a/tests/ui/traits/trait-upcasting/issue-11515.next.stderr b/tests/ui/traits/trait-upcasting/issue-11515.next.stderr
index 97d66cccb..da7ac4cc0 100644
--- a/tests/ui/traits/trait-upcasting/issue-11515.next.stderr
+++ b/tests/ui/traits/trait-upcasting/issue-11515.next.stderr
@@ -8,6 +8,6 @@ LL |     let test = Box::new(Test { func: closure });
    = help: add `#![feature(trait_upcasting)]` to the crate attributes to enable
    = note: required when coercing `Box<(dyn Fn() + 'static)>` into `Box<(dyn FnMut() + 'static)>`
 
-error: aborting due to previous error
+error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0658`.
diff --git a/tests/ui/traits/trait-upcasting/issue-11515.rs b/tests/ui/traits/trait-upcasting/issue-11515.rs
index 723f3a24f..31ea2fb35 100644
--- a/tests/ui/traits/trait-upcasting/issue-11515.rs
+++ b/tests/ui/traits/trait-upcasting/issue-11515.rs
@@ -1,5 +1,5 @@
 // revisions: current next
-//[next] compile-flags: -Ztrait-solver=next
+//[next] compile-flags: -Znext-solver
 
 struct Test {
     func: Box<dyn FnMut() + 'static>,
diff --git a/tests/ui/traits/trait-upcasting/migrate-lint-deny-regions.rs b/tests/ui/traits/trait-upcasting/migrate-lint-deny-regions.rs
new file mode 100644
index 000000000..da1a9cc27
--- /dev/null
+++ b/tests/ui/traits/trait-upcasting/migrate-lint-deny-regions.rs
@@ -0,0 +1,18 @@
+#![deny(deref_into_dyn_supertrait)]
+
+use std::ops::Deref;
+
+trait Bar<'a> {}
+trait Foo<'a>: Bar<'a> {}
+
+impl<'a> Deref for dyn Foo<'a> {
+    //~^ ERROR this `Deref` implementation is covered by an implicit supertrait coercion
+    //~| WARN this will change its meaning in a future release!
+    type Target = dyn Bar<'a>;
+
+    fn deref(&self) -> &Self::Target {
+        todo!()
+    }
+}
+
+fn main() {}
diff --git a/tests/ui/traits/trait-upcasting/migrate-lint-deny-regions.stderr b/tests/ui/traits/trait-upcasting/migrate-lint-deny-regions.stderr
new file mode 100644
index 000000000..a5f3660d4
--- /dev/null
+++ b/tests/ui/traits/trait-upcasting/migrate-lint-deny-regions.stderr
@@ -0,0 +1,19 @@
+error: this `Deref` implementation is covered by an implicit supertrait coercion
+  --> $DIR/migrate-lint-deny-regions.rs:8:1
+   |
+LL | impl<'a> Deref for dyn Foo<'a> {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `dyn Foo<'_>` implements `Deref<Target = dyn Bar<'_>>` which conflicts with supertrait `Bar<'_>`
+...
+LL |     type Target = dyn Bar<'a>;
+   |     -------------------------- target type is a supertrait of `dyn Foo<'_>`
+   |
+   = warning: this will change its meaning in a future release!
+   = note: for more information, see issue #89460 <https://github.com/rust-lang/rust/issues/89460>
+note: the lint level is defined here
+  --> $DIR/migrate-lint-deny-regions.rs:1:9
+   |
+LL | #![deny(deref_into_dyn_supertrait)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/traits/trait-upcasting/migrate-lint-deny.rs b/tests/ui/traits/trait-upcasting/migrate-lint-deny.rs
index d62418756..926b3649e 100644
--- a/tests/ui/traits/trait-upcasting/migrate-lint-deny.rs
+++ b/tests/ui/traits/trait-upcasting/migrate-lint-deny.rs
@@ -1,16 +1,14 @@
 #![deny(deref_into_dyn_supertrait)]
 
-extern crate core;
-
-use core::ops::Deref;
+use std::ops::Deref;
 
 // issue 89190
 trait A {}
 trait B: A {}
 
 impl<'a> Deref for dyn 'a + B {
-    //~^ ERROR `(dyn B + 'a)` implements `Deref` with supertrait `A` as target
-    //~| WARN this was previously accepted by the compiler but is being phased out;
+    //~^ ERROR this `Deref` implementation is covered by an implicit supertrait coercion
+    //~| WARN this will change its meaning in a future release!
 
     type Target = dyn A;
     fn deref(&self) -> &Self::Target {
diff --git a/tests/ui/traits/trait-upcasting/migrate-lint-deny.stderr b/tests/ui/traits/trait-upcasting/migrate-lint-deny.stderr
index 4533b1163..29997a9b3 100644
--- a/tests/ui/traits/trait-upcasting/migrate-lint-deny.stderr
+++ b/tests/ui/traits/trait-upcasting/migrate-lint-deny.stderr
@@ -1,13 +1,13 @@
-error: `(dyn B + 'a)` implements `Deref` with supertrait `A` as target
-  --> $DIR/migrate-lint-deny.rs:11:1
+error: this `Deref` implementation is covered by an implicit supertrait coercion
+  --> $DIR/migrate-lint-deny.rs:9:1
    |
 LL | impl<'a> Deref for dyn 'a + B {
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `dyn B` implements `Deref<Target = dyn A>` which conflicts with supertrait `A`
 ...
 LL |     type Target = dyn A;
-   |     -------------------- target type is set here
+   |     -------------------- target type is a supertrait of `dyn B`
    |
-   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = warning: this will change its meaning in a future release!
    = note: for more information, see issue #89460 <https://github.com/rust-lang/rust/issues/89460>
 note: the lint level is defined here
   --> $DIR/migrate-lint-deny.rs:1:9
@@ -15,5 +15,5 @@ note: the lint level is defined here
 LL | #![deny(deref_into_dyn_supertrait)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to previous error
+error: aborting due to 1 previous error
 
diff --git a/tests/ui/traits/trait-upcasting/migrate-lint-different-substs.rs b/tests/ui/traits/trait-upcasting/migrate-lint-different-substs.rs
new file mode 100644
index 000000000..8a90a09ff
--- /dev/null
+++ b/tests/ui/traits/trait-upcasting/migrate-lint-different-substs.rs
@@ -0,0 +1,21 @@
+// check-pass
+
+use std::ops::Deref;
+
+trait Bar<T> {}
+
+trait Foo: Bar<i32> {
+    fn as_dyn_bar_u32<'a>(&self) -> &(dyn Bar<u32> + 'a);
+}
+
+impl<'a> Deref for dyn Foo + 'a {
+    //~^ WARN this `Deref` implementation is covered by an implicit supertrait coercion
+    //~| WARN this will change its meaning in a future release!
+    type Target = dyn Bar<u32> + 'a;
+
+    fn deref(&self) -> &Self::Target {
+        self.as_dyn_bar_u32()
+    }
+}
+
+fn main() {}
diff --git a/tests/ui/traits/trait-upcasting/migrate-lint-different-substs.stderr b/tests/ui/traits/trait-upcasting/migrate-lint-different-substs.stderr
new file mode 100644
index 000000000..6245da5a1
--- /dev/null
+++ b/tests/ui/traits/trait-upcasting/migrate-lint-different-substs.stderr
@@ -0,0 +1,15 @@
+warning: this `Deref` implementation is covered by an implicit supertrait coercion
+  --> $DIR/migrate-lint-different-substs.rs:11:1
+   |
+LL | impl<'a> Deref for dyn Foo + 'a {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `dyn Foo` implements `Deref<Target = dyn Bar<u32>>` which conflicts with supertrait `Bar<i32>`
+...
+LL |     type Target = dyn Bar<u32> + 'a;
+   |     -------------------------------- target type is a supertrait of `dyn Foo`
+   |
+   = warning: this will change its meaning in a future release!
+   = note: for more information, see issue #89460 <https://github.com/rust-lang/rust/issues/89460>
+   = note: `#[warn(deref_into_dyn_supertrait)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/traits/trait-upcasting/multiple-occurrence-ambiguousity.stderr b/tests/ui/traits/trait-upcasting/multiple-occurrence-ambiguousity.stderr
index 0ad18be03..70ba1fcaf 100644
--- a/tests/ui/traits/trait-upcasting/multiple-occurrence-ambiguousity.stderr
+++ b/tests/ui/traits/trait-upcasting/multiple-occurrence-ambiguousity.stderr
@@ -9,6 +9,6 @@ LL |     let t: &dyn Bar<_> = s;
    = note: expected reference `&dyn Bar<_>`
               found reference `&dyn Foo`
 
-error: aborting due to previous error
+error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/traits/trait-upcasting/multiple_supertrait_upcastable.stderr b/tests/ui/traits/trait-upcasting/multiple_supertrait_upcastable.stderr
index ad80a009e..d075102b2 100644
--- a/tests/ui/traits/trait-upcasting/multiple_supertrait_upcastable.stderr
+++ b/tests/ui/traits/trait-upcasting/multiple_supertrait_upcastable.stderr
@@ -10,5 +10,5 @@ note: the lint level is defined here
 LL | #![deny(multiple_supertrait_upcastable)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to previous error
+error: aborting due to 1 previous error
 
diff --git a/tests/ui/traits/trait-upcasting/normalization.rs b/tests/ui/traits/trait-upcasting/normalization.rs
index c78338b0d..24da1ec5d 100644
--- a/tests/ui/traits/trait-upcasting/normalization.rs
+++ b/tests/ui/traits/trait-upcasting/normalization.rs
@@ -1,7 +1,7 @@
 // check-pass
 // issue: 114113
 // revisions: current next
-//[next] compile-flags: -Ztrait-solver=next
+//[next] compile-flags: -Znext-solver
 
 #![feature(trait_upcasting)]
 
diff --git a/tests/ui/traits/trait-upcasting/type-checking-test-1.current.stderr b/tests/ui/traits/trait-upcasting/type-checking-test-1.current.stderr
index b612005fc..10c22440a 100644
--- a/tests/ui/traits/trait-upcasting/type-checking-test-1.current.stderr
+++ b/tests/ui/traits/trait-upcasting/type-checking-test-1.current.stderr
@@ -4,6 +4,6 @@ error[E0605]: non-primitive cast: `&dyn Foo` as `&dyn Bar<_>`
 LL |     let _ = x as &dyn Bar<_>; // Ambiguous
    |             ^^^^^^^^^^^^^^^^ an `as` expression can only be used to convert between primitive types or to coerce to a specific trait object
 
-error: aborting due to previous error
+error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0605`.
diff --git a/tests/ui/traits/trait-upcasting/type-checking-test-1.next.stderr b/tests/ui/traits/trait-upcasting/type-checking-test-1.next.stderr
index b612005fc..10c22440a 100644
--- a/tests/ui/traits/trait-upcasting/type-checking-test-1.next.stderr
+++ b/tests/ui/traits/trait-upcasting/type-checking-test-1.next.stderr
@@ -4,6 +4,6 @@ error[E0605]: non-primitive cast: `&dyn Foo` as `&dyn Bar<_>`
 LL |     let _ = x as &dyn Bar<_>; // Ambiguous
    |             ^^^^^^^^^^^^^^^^ an `as` expression can only be used to convert between primitive types or to coerce to a specific trait object
 
-error: aborting due to previous error
+error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0605`.
diff --git a/tests/ui/traits/trait-upcasting/type-checking-test-1.rs b/tests/ui/traits/trait-upcasting/type-checking-test-1.rs
index afea8521e..54c3c5e0c 100644
--- a/tests/ui/traits/trait-upcasting/type-checking-test-1.rs
+++ b/tests/ui/traits/trait-upcasting/type-checking-test-1.rs
@@ -1,5 +1,5 @@
 // revisions: current next
-//[next] compile-flags: -Ztrait-solver=next
+//[next] compile-flags: -Znext-solver
 
 #![feature(trait_upcasting)]
 
diff --git a/tests/ui/traits/trait-upcasting/upcast-through-struct-tail.current.stderr b/tests/ui/traits/trait-upcasting/upcast-through-struct-tail.current.stderr
index 9f0993d65..f1f0cd309 100644
--- a/tests/ui/traits/trait-upcasting/upcast-through-struct-tail.current.stderr
+++ b/tests/ui/traits/trait-upcasting/upcast-through-struct-tail.current.stderr
@@ -8,6 +8,6 @@ LL |     x
    = help: add `#![feature(trait_upcasting)]` to the crate attributes to enable
    = note: required when coercing `Box<Wrapper<(dyn A + 'a)>>` into `Box<Wrapper<(dyn B + 'a)>>`
 
-error: aborting due to previous error
+error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0658`.
diff --git a/tests/ui/traits/trait-upcasting/upcast-through-struct-tail.next.stderr b/tests/ui/traits/trait-upcasting/upcast-through-struct-tail.next.stderr
index 9f0993d65..f1f0cd309 100644
--- a/tests/ui/traits/trait-upcasting/upcast-through-struct-tail.next.stderr
+++ b/tests/ui/traits/trait-upcasting/upcast-through-struct-tail.next.stderr
@@ -8,6 +8,6 @@ LL |     x
    = help: add `#![feature(trait_upcasting)]` to the crate attributes to enable
    = note: required when coercing `Box<Wrapper<(dyn A + 'a)>>` into `Box<Wrapper<(dyn B + 'a)>>`
 
-error: aborting due to previous error
+error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0658`.
diff --git a/tests/ui/traits/trait-upcasting/upcast-through-struct-tail.rs b/tests/ui/traits/trait-upcasting/upcast-through-struct-tail.rs
index 42495f45f..948f058e5 100644
--- a/tests/ui/traits/trait-upcasting/upcast-through-struct-tail.rs
+++ b/tests/ui/traits/trait-upcasting/upcast-through-struct-tail.rs
@@ -1,5 +1,5 @@
 // revisions: current next
-//[next] compile-flags: -Ztrait-solver=next
+//[next] compile-flags: -Znext-solver
 
 struct Wrapper<T: ?Sized>(T);