autopkgtest fails in hirsute on s390x

[Balint Reczey]

https://autopkgtest.ubuntu.com/packages/r/rust-debcargo/hirsute/s390x

https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-hirsute/hirsute/s390x/r/rust-debcargo/20210316_172308_209b5@/log.gz
...
error[E0220]: associated type `Item` not found for `L`
   --> /tmp/tmp.QJ2SP1flgi/registry/either-1.5.0/src/lib.rs:380:41
    |
380 | R: IntoIterator<Item = L::Item>
    | ^^^^ associated type `Item` not found

error[E0220]: associated type `IntoIter` not found for `L`
   --> /tmp/tmp.QJ2SP1flgi/registry/either-1.5.0/src/lib.rs:378:41
    |
378 | pub fn into_iter(self) -> Either<L::IntoIter, R::IntoIter>
    | ^^^^^^^^ associated type `IntoIter` not found

error[E0220]: associated type `IntoIter` not found for `R`
   --> /tmp/tmp.QJ2SP1flgi/registry/either-1.5.0/src/lib.rs:378:54
    |
378 | 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`
...

[Brian Murray (brian-murray)]

This seems sorted out now.