bug#36882: Qemu 4.2.0 build for x86_64-linux fails

[Mathieu Othacehe]

Hello Janneke,

> Do you have a patch/branch where I can see this related error?  If mes
> builds are an exception, it could be nice to solve it there?  Or is
> this a Qemu thing and is Qemu the only package that suffers from this?
>
> Trying to help here, but I'm not sure if I understand what's going on...

To summarize the situation, we are considering adding a dirty hack in
gnu-build-system so that "libc" input is removed from
C_INCLUDE_PATH. The reason is that GCC has already a libc hardcoded in
its include search-path. Having both libc, causes build failures for
QEMU on core-updates and possibly other programs playing around
-m<something> and -ffreestanding in GCC.

Anyway, Mes does not break anything, it's just that removing "libc"
input unconditionally in set-paths breaks Mes packages. That's why
Marius was suggesting renaming "libc" to "mes-libc" or something, so
that we can proceed.

Thanks,

Mathieu