Clang on FreeBSD fails to compile quantizer.cpp

[stemann]

Clang on the latest FreeBSD, 13.4, and 14.2, is unhappy with the sims::Simd calls in quantizer.cpp L167-L168: error: implicit instantiation of undefined template 'mlx::core::simd::Simd<unsigned int, 4>, cf.
https://buildkite.com/julialang/yggdrasil/builds/17042#0194c6a1-5b8d-4a7c-8cef-8e098d29b750/6-32274

[awni]

The basic problem is

if constepxr (false) {
 // code <- this shouldn't be compiled but is
} else {
// other code
} 

Probably we can resolve this using a template instead of a constexpr

[stemann]

Ah OK.

That’s a bit annoying though - that a single compiler/platform combo is restricting the programming style.

It’s also possible to just not build for FreeBSD - though that would also be a pity.

[awni]

I don't have an easy way to test on a FreeBSD... there is no github runner for it as far as I can tell and it's not in CircleCI. How do you do CI on that platform?

[stemann]

I can currently only compile. I use BinaryBuilder, to cross-compile for FreeBSD etc. in a Linux-based build environment - by executing the build recipe in build_tarballs.jl from https://github.com/JuliaPackaging/Yggdrasil/tree/master/M/MLX

You only need a Linux system, or a Mac with Docker, and an ancient Julia version (version 1.7), which you can get most easily via https://github.com/JuliaLang/juliaup

juliaup add 1.7

julia +1.7 --eval '
  using Pkg
  Pkg.add("BinaryBuilder")
'

BINARYBUILDER_USE_CCACHE=true julia +1.7 build_tarballs.jl --debug=error --verbose aarch64-unknown-freebsd

This will start a build for FreeBSD and will drop you into a shell in the cross compile env. in case of failure.

... but in order to have the latest FreeBSD version (14.2), you will want to use the build_tarballs.jl recipe from JuliaPackaging/Yggdrasil#10374

[ararslan]

there is no github runner for it as far as I can tell and it's not in CircleCI. How do you do CI on that platform?

With GitHub Actions you can use vmactions/freebsd-vm. It generally works well (and is used by JuliaUp, the tool mentioned above) though the jobs take longer to execute due to the VM setup and teardown and copying files back and forth. If you're open to using a different CI provider, Cirrus CI supports FreeBSD natively.