Build failure with c2hs involving __v8hf

[sheaf]

I'm getting the following build failure when building hw-json-simd:

Configuring library for hw-json-simd-0.1.1.2..
Preprocessing library for hw-json-simd-0.1.1.2..
c2hs: C header contains errors:

/nix/store/kf147vkmb7a7z17lkpgj2d6y7w75nf7v-gcc-12.2.0/lib/gcc/x86_64-unknown-linux-gnu/12.2.0/include/avx512fp16intrin.h:38: (column 18) [ERROR]  >>> Syntax error !
  The symbol `__v8hf' does not fit here.

[sheaf]

A very silly workaround is:

• comment out #include <immintrin.h> in cbits/intrinsics.h
• start building the package, it will error out
• comment back in the include
• try building the package again; the recompilation logic won't try to start from the beginning, and it will be possible to finish compilation

[sheaf]

This error seems to be specific to nix. Further discussion of the issue can be found here; it concludes:

Thus it appears the error message is coming from c2hs trying to use whatever gcc was used to build GHC.

[tbidne]

@sheaf I actually noticed your (this) issue when I ran into this problem myself in the issue you linked (sorry, should have pinged you). I have yet to make any more progress, however...