`bitflags` stuck at v1 from 2021

[git-staus]

In beab6cf last year @Firestar99 downgraded bitflags in spirv-std to version 1.3.2 because the "backend fails with 2.X". This of course causes two instances of bitflags to be compiled in when rust-gpu is used alongside e.g. cargo-gpu-install or vulkano.

I tried upgrading spirv-std to the latest bitflags 2.11.0 anyway but I did not notice any apparent issues when building or running tests on today's main, but I have not a clue if I am doing it right.

[Firestar99]

The commit links to #349 where I left this comment:

For some reason, our backend doesn't like the following expression which bitflags 2.X expands to. I downgraded it back to 1.X for now. eddyb any ideas?

error: cannot offset a pointer to an arbitrary element
    --> /home/firestar99/workspace/rust-gpu/crates/spirv-std/src/ray_tracing.rs:675:28
     |
675  |                 let flag = <RayFlags as bitflags::Flags>::FLAGS[i].value().bits();
     |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     |

Curious to hear it just works right now, cause I don't remember us changing anything that may lead to this being fixed.

Feel free to PR in the version upgrade, I'll have a look if I can find the cause why this suddenly works.

[git-staus]

I completely missed the link back to that issue, thanks!

[Firestar99]

Upgrading to bitflags@2 on current main still fails the ray_query_get_ray_flags_khr compiletest (cargo compiletest ray_flags optional --bless), by that test calling RayFlags::from_bits_truncate(..) (via get_ray_flags()) which causes the compile error

[git-staus]

You're so fast! My laptop is still frying my thighs running the tests on unmodified main as a sanity check.

In that case the downgrade is still adequate and I have peace of mind telling Clippy to shut up. I suppose this issue could be left open to document this work-around until fixing it becomes feasible.