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

["Ludovic Courtès" <ludo@gnu.org>]

Hi,

Mathieu Othacehe <m.othacehe@gmail.com> skribis:

> About the environment issue, we have the same problem on master. You can
> run the following command:
>
>  ./pre-inst-env guix environment -C -e '(@@ (gnu packages commencement)
>  coreutils-final)' -- echo -e '#include <stdint.h>\n int main() {return
>  0;}' > test.c && gcc -m16 -ffreestanding test.c
>
>
> and see that in takes stdint.h from the profile glibc header:
>
> In file included from /gnu/store/nl6zndkx4115laq50qmqcvnzinfz5rk0-profile/include/features.h:474:0,
>                  from /gnu/store/nl6zndkx4115laq50qmqcvnzinfz5rk0-profile/include/bits/libc-header-start.h:33,
>                  from /gnu/store/nl6zndkx4115laq50qmqcvnzinfz5rk0-profile/include/stdint.h:26,
>                  from test.c:1:
> /gnu/store/nl6zndkx4115laq50qmqcvnzinfz5rk0-profile/include/gnu/stubs.h:7:11: fatal error: gnu/stubs-32.h: No such file or directory
>  # include <gnu/stubs-32.h>
>            ^~~~~~~~~~~~~~~~

Indeed.

> So if it's ok for you, I'll try to implement a GCC hack so that we can
> keep using C_INCLUDE_PATH on core-updates and have QEMU building, as you
> proposed.
>
> About the environment use-case, it's getting really tricky, but as it is
> not a regression, we can maybe postpone the resolution.

Yes, both make sense to me.

>> Incidentally, do we have problems building anything other than QEMU?
>
> I don't know, but potentially any program building with -m<something>
> and -ffreestanding fails on core-updates.

The evil idea I was getting at was that, if that’s just a couple of
packages, we can fix them locally.  Evil plan in case the better hack
turns out to be tricky.  :-)

Ludo’.