Rust compilation requirements

[verdurin]

I'm trying to update the EasyBuild easyconfig for SKA2 to version 0.5.0.

After finalising the crates list, I see this error:

   Compiling ska v0.5.0 (/dev/shm/SKA2/0.5.0/GCCcore-13.3.0/easybuild_vendor/ska-0.5.0)
error[E0658]: use of unstable library feature `unsigned_is_multiple_of`
   --> src/ska_dict.rs:118:28
    |
118 |             if !iter_reads.is_multiple_of(step) {
    |                            ^^^^^^^^^^^^^^
    |
    = note: see issue #128101 <https://github.com/rust-lang/rust/issues/128101> for more information

Looking at the upstream issue, it seems that you're using a feature merged in Rust 1.87 so that is the minimum requirement when building from source - is that correct?

[johnlees]

I am using v1.88 locally, CI is 1.90

Would it help to specify that here, for your recipe?

[RagnarGrootKoerkamp]

A nice way to give a beter error message is to set the minimum rust version. Along the lines of: RagnarGrootKoerkamp/sassy@69c88b9

Ah @johnlees I see that's also what you linked. So I think that's just a check, but not an instruction to use a specific version. Instead, the rust-toolchain.toml file can indicate a specific version or just stable, but I'm not sure whether that's always picked up. => quick testing shows that if I put 1.92 (the next version), cargo build automatically tries to download that (via rustup) and then fails because it's not out yet, so that could be a solution. Just stable probably won't force-update stale versions. But pinning a specific version also isn't ideal because it won't allow later versions.