'either' fails to compile on s390x

[dot-asm]

The problem appears to be s390x-specific. At least I failed to spot another target that would fail.

Code

To reproduce the problem

• cargo new foo
• cd foo
• add either = "^1.6" to [dependencies] in Cargo.toml
• cargo check

I expected to see this happen: successful completion of cargo check

Instead, this happened: failure to compile either, see below for error messages

Version it worked on

It most recently worked on: 1.49.0

Version with regression

rustc --version --verbose:

rustc 1.50.0 (cb75ad5db 2021-02-10)
binary: rustc
commit-hash: cb75ad5db02783e8b0222fee363c5f63f7e2cf5b
commit-date: 2021-02-10
host: s390x-unknown-linux-gnu
release: 1.50.0

Backtrace

Backtrace

    Checking either v1.6.1
     Running `rustc --crate-name either /home/appro/.cargo/registry/src/github.tiyicn.workers.dev-eae4ba8cbf2ce1c7/either-1.6.1/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi --crate-type lib --emit=dep-info,metadata -C embed-bitcode=no -C debuginfo=2 --cfg 'feature="default"' --cfg 'feature="use_std"' -C metadata=98ea2ad6c29b0e25 -C extra-filename=-98ea2ad6c29b0e25 --out-dir /home/appro/a/foo/target/debug/deps -L dependency=/home/appro/a/foo/target/debug/deps --cap-lints allow`
error[E0220]: associated type `Item` not found for `L`
   --> /home/appro/.cargo/registry/src/github.tiyicn.workers.dev-eae4ba8cbf2ce1c7/either-1.6.1/src/lib.rs:394:35
    |
394 |         R: IntoIterator<Item = L::Item>,
    |                                   ^^^^ associated type `Item` not found

error[E0220]: associated type `IntoIter` not found for `L`
   --> /home/appro/.cargo/registry/src/github.tiyicn.workers.dev-eae4ba8cbf2ce1c7/either-1.6.1/src/lib.rs:391:41
    |
391 |     pub fn into_iter(self) -> Either<L::IntoIter, R::IntoIter>
    |                                         ^^^^^^^^ associated type `IntoIter` not found

error[E0220]: associated type `IntoIter` not found for `R`
   --> /home/appro/.cargo/registry/src/github.tiyicn.workers.dev-eae4ba8cbf2ce1c7/either-1.6.1/src/lib.rs:391:54
    |
391 |     pub fn into_iter(self) -> Either<L::IntoIter, R::IntoIter>
    |                                                      ^^^^^^^^ associated type `IntoIter` not found

error: aborting due to 3 previous errors

For more information about this error, try `rustc --explain E0220`.
error: could not compile `either`

Caused by:
  process didn't exit successfully: `rustc --crate-name either /home/appro/.cargo/registry/src/github.tiyicn.workers.dev-eae4ba8cbf2ce1c7/either-1.6.1/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi --crate-type lib --emit=dep-info,metadata -C embed-bitcode=no -C debuginfo=2 --cfg 'feature="default"' --cfg 'feature="use_std"' -C metadata=98ea2ad6c29b0e25 -C extra-filename=-98ea2ad6c29b0e25 --out-dir /home/appro/a/foo/target/debug/deps -L dependency=/home/appro/a/foo/target/debug/deps --cap-lints allow` (exit code: 1)

@rustbot modify labels: +regression-from-stable-to-stable -regression-untriaged

[jyn514]

@dot-asm how did you get your rust compiler? #80810 may be related.

[dot-asm]

I've initially noted the failure on travis-ci.com and then reduced it to the minimal setup with boilerplate project with single dependency on a s390x system. On travis it is was auto-updated by travis itself. And on "a s390x system" it was freshly installed with curl ... | sh.

[dot-asm]

#80810 may be related.

Yes, appears as duplicate. Sorry about the noise.

As potentially relevant additional info, travis runs Ubuntu 16, and "a s390x system" - a seasoned SuSE 12.

[jyn514]

Ok, closing as a duplicate of #80810 then. Thanks for the report.