Closed
Description
openedon Aug 26, 2024
Our CI started failing with the nightly compiler, for a day.
Code
I tried this code:
struct Foo {}
impl Foo {
fn set(&self, _: bool) {}
}
fn main() {
let foo = Foo {};
let foo : core::pin::Pin<&Foo> = core::pin::Pin::new(&foo);
foo.set(true);
}It compiles in stable, but not with the nightly compiler:
error[E0277]: the trait bound `&Foo: DerefMut` is not satisfied
--> src/main.rs:27:9
|
27 | foo.set(true);
| ^^^ the trait `DerefMut` is not implemented for `&Foo`
|
note: required by a bound in `Pin::<Ptr>::set`
--> /home/olivier/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/pin.rs:1478:14
|
1476 | pub fn set(&mut self, value: Ptr::Target)
| --- required by a bound in this associated function
1477 | where
1478 | Ptr: DerefMut,
| ^^^^^^^^ required by this bound in `Pin::<Ptr>::set`
help: consider mutably borrowing here
|
27 | (&mut foo).set(true);
| +++++ +
error[E0308]: mismatched types
--> src/main.rs:27:13
|
27 | foo.set(true);
| --- ^^^^ expected `Foo`, found `bool`
| |
| arguments to this method are incorrect
|
note: method defined here
--> /home/olivier/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/pin.rs:1476:12
|
1476 | pub fn set(&mut self, value: Ptr::Target)
| ^^^
Version it worked on
It works in beta (1.81), it only started failing with nightly very recently (one or two day)
Version with regression
rustc 1.82.0-nightly (c6db1ca3c 2024-08-25)
binary: rustc
commit-hash: c6db1ca3c93ad69692a4c4b5542f26fda4bf3aec
commit-date: 2024-08-25
host: x86_64-unknown-linux-gnu
release: 1.82.0-nightly
LLVM version: 19.1.0
Looking at the recent history, I believe the regression is caused by b968b26 (#129449)
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