dev-lang/python-3.11.3: fix build on macOS.

[biergaizi]

Currently, dev-lang/python-3.11.3 is unbuildable on macOS for two reasons. First, due to a hardcoded dependency sys-apps/util-linux. This commit fixes it by conditionally requiring sys-apps/util-linux only on "kernel_linux".

Another problem is that there exists two "#ifdef" checks for the system calls mkfifoat() and mknodat(), which are not compatible with GCC. Because they're defined using the __builtin_available() function - specific to clang without a fallback for GCC, they're never defined, thus creating the following errors:

./Modules/posixmodule.c:15647:23: error: 'HAVE_MKFIFOAT_RUNTIME'
undeclared (first use in this function); did you mean
'HAVE_MKDIRAT_RUNTIME'?
./Modules/posixmodule.c:15651:22: error: 'HAVE_MKNODAT_RUNTIME'
undeclared (first use in this function); did you mean
'HAVE_MKDIRAT_RUNTIME'?

These two checks were originally introduced to fix the problem that building Python on the macOS 13 SDK but running it on an earlier macOS version would result in a segfault. Since moving Gentoo Prefix in this manner is not supported, as a temporary fix, we simply revert this patch. Since this change only has an effect on macOS, it's safe to apply it without checking whether we're running on Darwin.

Closes: https://bugs.gentoo.org/905618

[grobian]

hmmm, I'll rebuild on 13.3.1, but I'm sure this succeed fine yesterday

[grobian]

ok, it still compiles for me

[biergaizi]

ok, it still compiles for me

How is it even possible when it has an unsatisfiable dependency sys-apps/util-linux?

[grobian]

you can just use ebuild bla.ebuild install, but I fixed the dependency an hour ago or so

[biergaizi]

I'm pretty sure that undefined HAVE_MKFIFOAT_RUNTIME and HAVE_MKNODAT_RUNTIME are a real problem, as I can reliably replicate the problem on macOS 13.2 (Darwin 22.3) on ARM64, with both GCC 12.1 and GCC 12.2, and with both unmodified upstream source, and with Portage ebuild. A Python dev has already wrote a patch, which is now waiting to enter the upstream.

I plan to rework on this pull request and update my patch to the upstream version.

arm64-apple-darwin22-gcc  -Wsign-compare -DNDEBUG     -O2 -pipe -march=native -fwrapv -std=c11 -Wextra -Wno-unused-parameter -Wno-missing-field-initializers -Wstrict-prototypes -Werror=implicit-function-declaration -fvisibility=hidden  -I./Include/internal  -I. -I./Include -I/Users/gentoo/gentoo/usr/include/ncursesw/ -I/Users/gentoo/gentoo/usr/include/ncursesw   -DPy_BUILD_CORE_BUILTIN -c ./Modules/_collectionsmodule.c -o Modules/_collectionsmodule.o
./Modules/posixmodule.c: In function 'probe_mkfifoat':
./Modules/posixmodule.c:15647:23: error: 'HAVE_MKFIFOAT_RUNTIME' undeclared (first use in this function); did you mean 'HAVE_MKDIRAT_RUNTIME'?
15647 | PROBE(probe_mkfifoat, HAVE_MKFIFOAT_RUNTIME)
      |                       ^~~~~~~~~~~~~~~~~~~~~
./Modules/posixmodule.c:15611:11: note: in definition of macro 'PROBE'
15611 |       if (test) {        \
      |           ^~~~
./Modules/posixmodule.c: In function 'probe_mknodat':
./Modules/posixmodule.c:15651:22: error: 'HAVE_MKNODAT_RUNTIME' undeclared (first use in this function); did you mean 'HAVE_MKDIRAT_RUNTIME'?
15651 | PROBE(probe_mknodat, HAVE_MKNODAT_RUNTIME)
      |                      ^~~~~~~~~~~~~~~~~~~~
./Modules/posixmodule.c:15611:11: note: in definition of macro 'PROBE'
15611 |       if (test) {        \
      |           ^~~~
make: *** [Makefile:2697: Modules/posixmodule.o] Error 1
make: *** Waiting for unfinished jobs....
 * ERROR: dev-lang/python-3.11.3::gentoo_prefix failed (compile phase):
 *   emake failed
 * 
 * If you need support, post the output of `emerge --info '=dev-lang/python-3.11.3::gentoo_prefix'`,
 * the complete build log and the output of `emerge -pqv '=dev-lang/python-3.11.3::gentoo_prefix'`.
 * The complete build log is located at '/Users/gentoo/gentoo/var/tmp/portage/dev-lang/python-3.11.3/temp/build.log'.
 * The ebuild environment file is located at '/Users/gentoo/gentoo/var/tmp/portage/dev-lang/python-3.11.3/temp/environment'.
 * Working directory: '/Users/gentoo/gentoo/var/tmp/portage/dev-lang/python-3.11.3/work/Python-3.11.3'
 * S: '/Users/gentoo/gentoo/var/tmp/portage/dev-lang/python-3.11.3/work/Python-3.11.3'

[grobian]

I think the difference is that I use a 12-based prefix on 13 still.

[biergaizi]

I think the difference is that I use a 12-based prefix on 13 still.

I've updated the Pull Request with the new official upstream patch, please review the change again.

[biergaizi]

I just realized that it has already been included into Gentoo Prefix Python patches-r1, no further change is needed.

[biergaizi]

@grobian I found the patch you've just committed into the Prefix tree is broken, please fix it as soon as possible, see python/cpython#104129 (comment) for more information, thanks.

The broken patch was committed into the Gentoo Prefix tree at 2023-05-04 07:33:30 UTC, meanwhile I already pointed out that the upstream patch is broken to the upstream Python developers at 2023-05-03 22:44:34 UTC, which was then fixed at 2023-05-04 01:17:25 UTC.

It should've been preventable.