Re: Cross building packages with `libgomp-devel` in makedepends breaks the masterdir

[tornaria <tornaria@users.noreply.github.com>]

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New comment by tornaria on void-packages repository

https://github.com/void-linux/void-packages/issues/31055#issuecomment-1008935998

Comment:
I know what happens with siril:
```
$ grep Libs: /usr/aarch64-linux-gnu/usr/lib/pkgconfig/libraw.pc 
Libs: -L${libdir} -lraw -lstdc++ -fopenmp
```
Since siril links to libraw, it will inherit the `-fopenmp` flag thus requiring libgomp-devel.

Normally _for cross builds_  this is not a problem since libgomp-devel is implicit. But note that for non-cross builds on aarch64 this would still be a problem.

Maybe a package having `-fopenmp` in its pkgconfig should depend on `libgomp-devel` to avoid this breakage.

Why is this happening? My guess is that when cross building libraw detects openmp is available at compile time so it uses it. When nocross building libraw doesn't use openmp.

Random thoughts:
 - if libraw can use openmp, maybe we want to use it for nocross as well, so add libgomp-devel explicitly
 - maybe a hook should check if `-fopenmp` is in some pkgconfig but `libgomp-devel` is not in depends and error out?
 - if `libgomp-devel` is implicit in every cross build, shouldn't also be implicit in every nocross build? Maybe more programs can benefit from openmp (e.g. siril itself I think can use openmp, not only indirectly via libraw).