Don't trigger never type lint in a delegation test

Author: WaffleLapkin

tests/ui/delegation/unsupported.rs

@@ -10,15 +10,11 @@ mod opaque {
     mod to_reuse {
         use super::Trait;
 
-        pub fn opaque_ret() -> impl Trait { unimplemented!() }
-        //~^ warn: this function depends on never type fallback being `()`
-        //~| warn: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+        pub fn opaque_ret() -> impl Trait { () }
     }
 
     trait ToReuse {
-        fn opaque_ret() -> impl Trait { unimplemented!() }
-        //~^ warn: this function depends on never type fallback being `()`
-        //~| warn: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+        fn opaque_ret() -> impl Trait { () }
     }
 
     // FIXME: Inherited `impl Trait`s create query cycles when used inside trait impls.

tests/ui/delegation/unsupported.stderr

@@ -1,74 +1,43 @@
-error[E0391]: cycle detected when computing type of `opaque::<impl at $DIR/unsupported.rs:25:5: 25:24>::{synthetic#0}`
-  --> $DIR/unsupported.rs:26:25
+error[E0391]: cycle detected when computing type of `opaque::<impl at $DIR/unsupported.rs:21:5: 21:24>::{synthetic#0}`
+  --> $DIR/unsupported.rs:22:25
    |
 LL |         reuse to_reuse::opaque_ret;
    |                         ^^^^^^^^^^
    |
 note: ...which requires comparing an impl and trait method signature, inferring any hidden `impl Trait` types in the process...
-  --> $DIR/unsupported.rs:26:25
+  --> $DIR/unsupported.rs:22:25
    |
 LL |         reuse to_reuse::opaque_ret;
    |                         ^^^^^^^^^^
-   = note: ...which again requires computing type of `opaque::<impl at $DIR/unsupported.rs:25:5: 25:24>::{synthetic#0}`, completing the cycle
-note: cycle used when checking that `opaque::<impl at $DIR/unsupported.rs:25:5: 25:24>` is well-formed
-  --> $DIR/unsupported.rs:25:5
+   = note: ...which again requires computing type of `opaque::<impl at $DIR/unsupported.rs:21:5: 21:24>::{synthetic#0}`, completing the cycle
+note: cycle used when checking that `opaque::<impl at $DIR/unsupported.rs:21:5: 21:24>` is well-formed
+  --> $DIR/unsupported.rs:21:5
    |
 LL |     impl ToReuse for u8 {
    |     ^^^^^^^^^^^^^^^^^^^
    = 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
 
-warning: this function depends on never type fallback being `()`
-  --> $DIR/unsupported.rs:13:9
-   |
-LL |         pub fn opaque_ret() -> impl Trait { unimplemented!() }
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = 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 #123748 <https://github.com/rust-lang/rust/issues/123748>
-   = help: specify the types explicitly
-note: in edition 2024, the requirement `!: opaque::Trait` will fail
-  --> $DIR/unsupported.rs:13:32
-   |
-LL |         pub fn opaque_ret() -> impl Trait { unimplemented!() }
-   |                                ^^^^^^^^^^
-   = note: `#[warn(dependency_on_unit_never_type_fallback)]` on by default
-
-warning: this function depends on never type fallback being `()`
-  --> $DIR/unsupported.rs:19:9
-   |
-LL |         fn opaque_ret() -> impl Trait { unimplemented!() }
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = 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 #123748 <https://github.com/rust-lang/rust/issues/123748>
-   = help: specify the types explicitly
-note: in edition 2024, the requirement `!: opaque::Trait` will fail
-  --> $DIR/unsupported.rs:19:28
-   |
-LL |         fn opaque_ret() -> impl Trait { unimplemented!() }
-   |                            ^^^^^^^^^^
-
-error[E0391]: cycle detected when computing type of `opaque::<impl at $DIR/unsupported.rs:28:5: 28:25>::{synthetic#0}`
-  --> $DIR/unsupported.rs:29:24
+error[E0391]: cycle detected when computing type of `opaque::<impl at $DIR/unsupported.rs:24:5: 24:25>::{synthetic#0}`
+  --> $DIR/unsupported.rs:25:24
    |
 LL |         reuse ToReuse::opaque_ret;
    |                        ^^^^^^^^^^
    |
 note: ...which requires comparing an impl and trait method signature, inferring any hidden `impl Trait` types in the process...
-  --> $DIR/unsupported.rs:29:24
+  --> $DIR/unsupported.rs:25:24
    |
 LL |         reuse ToReuse::opaque_ret;
    |                        ^^^^^^^^^^
-   = note: ...which again requires computing type of `opaque::<impl at $DIR/unsupported.rs:28:5: 28:25>::{synthetic#0}`, completing the cycle
-note: cycle used when checking that `opaque::<impl at $DIR/unsupported.rs:28:5: 28:25>` is well-formed
-  --> $DIR/unsupported.rs:28:5
+   = note: ...which again requires computing type of `opaque::<impl at $DIR/unsupported.rs:24:5: 24:25>::{synthetic#0}`, completing the cycle
+note: cycle used when checking that `opaque::<impl at $DIR/unsupported.rs:24:5: 24:25>` is well-formed
+  --> $DIR/unsupported.rs:24:5
    |
 LL |     impl ToReuse for u16 {
    |     ^^^^^^^^^^^^^^^^^^^^
    = 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: recursive delegation is not supported yet
-  --> $DIR/unsupported.rs:42:22
+  --> $DIR/unsupported.rs:38:22
    |
 LL |         pub reuse to_reuse2::foo;
    |                              --- callee defined here
@@ -77,14 +46,14 @@ LL |     reuse to_reuse1::foo;
    |                      ^^^
 
 error[E0283]: type annotations needed
-  --> $DIR/unsupported.rs:52:18
+  --> $DIR/unsupported.rs:48:18
    |
 LL |     reuse Trait::foo;
    |                  ^^^ cannot infer type
    |
    = note: cannot satisfy `_: effects::Trait`
 
-error: aborting due to 4 previous errors; 2 warnings emitted
+error: aborting due to 4 previous errors
 
 Some errors have detailed explanations: E0283, E0391.
 For more information about an error, try `rustc --explain E0283`.