bug#30756: GCC >= 6 '-isystem' and C_INCLUDE_PATH behavior changed, breaking

[Ludovic Courtès]

Hi,

Maxim Cournoyer <address@hidden> skribis:

> It'd be nice to find a correct solution, but it seems I can't even make
> the build system of Inkscape work after switching from CPATH to
> CPLUS_INCLUDE_PATH and stripping it from any glibc/gcc include
> directories (I don't get the "stdlib.h: No such file or directory."
> error anymore, but I now get:
> "/gnu/store/zw5f5g5aqlxam3imaylfla0i98nkridf-glibc-2.30/include/bits/errno.h:26:11:
> fatal error: linux/errno.h: No such file or directory" instead, which I
> don't understand).
>
> I also tried moving the glibc include directory to the end of
> CPLUS_INCLUDE_PATH and it would still wouldn't be happy.  Hmmph!

Oh, really?  I think that, as Mark H Weaver mentioned in this thread, if
we make sure that glibc comes next-to-last (before Linux-libre headers)
and appears only once in the list, it should work.

Can you confirm?

Thanks,
Ludo’.