0.15 not compatible with 1.63 despite rust-version hint #574
Description
On PyO3's MSRV CI runs (also 1.63, which hashbrown has in its Cargo.toml) we are getting runtime panics from atomic orderings incompatible with 1.63.
It looks like the root cause is the new foldhash dependency, which does not have any rust-version in its Cargo.toml. The code in question has existed since the first release of foldhash, so I can only conclude that crate does not support 1.63 at all, and thus hashbrown can't either.
https://github.com/PyO3/pyo3/actions/runs/11271186265/job/31344727179#step:18:957
thread 'conversions::hashbrown::tests::test_extract_hashbrown_hashset' panicked at 'a failure ordering can't be stronger than a success ordering', /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/core/src/sync/atomic.rs:2700:18
stack backtrace:
0: rust_begin_unwind
at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/panicking.rs:584:5
1: core::panicking::panic_fmt
at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/core/src/panicking.rs:142:14
2: core::sync::atomic::atomic_compare_exchange_weak
at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/core/src/sync/atomic.rs:2700:18
3: core::sync::atomic::AtomicU8::compare_exchange_weak
at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/core/src/sync/atomic.rs:1937:21
4: foldhash::seed::global::GlobalSeed::init_slow
at /home/runner/.cargo/registry/src/github.com-1ecc6299db9ec823/foldhash-0.1.3/src/seed.rs:277:23
5: foldhash::seed::global::GlobalSeed::new
at /home/runner/.cargo/registry/src/github.com-1ecc6299db9ec823/foldhash-0.1.3/src/seed.rs:263:17
6: <foldhash::seed::fast::RandomState as core::default::Default>::default
at /home/runner/.cargo/registry/src/github.com-1ecc6299db9ec823/foldhash-0.1.3/src/seed.rs:72:30
7: <hashbrown::set::HashSet<T,S,A> as core::iter::traits::collect::FromIterator<T>>::from_iter
at /home/runner/.cargo/registry/src/github.com-1ecc6299db9ec823/hashbrown-0.15.0/src/set.rs:1271:44