GeezerVison is showing github.com — failure building Python 3.15.0a3 through 3.15.0 release on Alpine · Issue #143632 · python/cpython
failure building Python 3.15.0a3 through 3.15.0 release on Alpine #143632DescriptionWhen building Python 3.15.0a3 - 3.15.0 on Alpine Linux 3.23 (or 3.24) (musl libc) on certain architectures, the build fails with error: redefinition of 'struct prctl_mm_map' (full error below).
This is related to the changes added in #142079. TL;DR: in musl libc, some kernel structs are redefined in the musl-provided headers. In this case sys/prctl.h redefines a struct in linux/prctl.h; see also https://wiki.musl-libc.org/faq.html#Q:-Why-am-I-getting-.
Configure setup:
gnuArch="$(dpkg-architecture --query DEB_BUILD_GNU_TYPE)"
./configure \
--build="$gnuArch" \
--enable-loadable-sqlite-extensions \
--enable-option-checking=fatal \
--enable-shared \
--with-lto \
--with-ensurepip
# --with-lto is not used on riscv64 Make lines, per architecture:
# nproc is used for the number of jobs, so it varies by system
# amd64 and arm64v8
make -j 8 'EXTRA_CFLAGS=-DTHREAD_STACK_SIZE=0x100000 -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer' 'LDFLAGS=-Wl,--strip-all'
# i386 (x86)
make -j 8 'EXTRA_CFLAGS=-DTHREAD_STACK_SIZE=0x100000' 'LDFLAGS=-Wl,--strip-all'
# arm32v6, arm32v7, ppc64le, riscv64, s390x
make -j 8 'EXTRA_CFLAGS=-DTHREAD_STACK_SIZE=0x100000 -fno-omit-frame-pointer' 'LDFLAGS=-Wl,--strip-all' When building on arm32v6, arm32v7, i386, and ppc64le, the configure check for PR_SET_VMA_ANON_NAME succeeds and so it is attempted to be used during build, but during build, it fails with the following error:
$ # configure line:
checking whether PR_SET_VMA_ANON_NAME is declared... yes
$ # build error during "make"
In file included from ./Include/internal/pycore_mmap.h:25,
from Objects/obmalloc.c:5:
/usr/include/sys/prctl.h:88:8: error: redefinition of 'struct prctl_mm_map'
88 | struct prctl_mm_map {
| ^~~~~~~~~~~~
In file included from ./Include/internal/pycore_mmap.h:24:
/usr/include/linux/prctl.h:134:8: note: originally defined here
134 | struct prctl_mm_map {
| ^~~~~~~~~~~~But on amd64, arm64v8, riscv64, and s390x (or any arch on Alpine 3.22), the same error is encountered during the configure check, so the feature is disabled, and it doesn't cause a build error.
$ # configure.log
configure:23951: checking whether PR_SET_VMA_ANON_NAME is declared
configure:23951: gcc -c conftest.c >&5
In file included from conftest.c:415:
/usr/include/sys/prctl.h:103:1: error: redefinition of struct or union 'struct prctl_mm_map'
103 | };
| ^
In file included from conftest.c:414:
/usr/include/linux/prctl.h:134:8: note: originally defined here
134 | struct prctl_mm_map {
| ^~~~~~~~~~~~
configure:23951: $? = 1So, what is weird to me, is that the AC_CHECK_DECLS([PR_SET_VMA_ANON_NAME], succeeded on some architectures and then the same set of includes failed when in Include/internal/pycore_mmap.h. But also, this new feature is silently disabled (even if available in the kernel headers) because the configure check fails on Alpine because of the redefined struct in musl libc.
I think an #ifdef __GLIBC__ or similar could be used to only include both headers when using glibc, but maybe it is more complex than that.
Full build setup: https://github.com/docker-library/python/blob/ac65a0ec34172eb865a8cef47fed3dc71a38d419/3.15-rc/alpine3.23/Dockerfile
Full build log: https://doi-janky.infosiftr.net/job/meta/view/builds/job/arm32v7/job/build/88902/console
Linked PRs
Activitytianon commented on Mar 20, 2026 We're still seeing failures that look like this while building python:3.15.0a7-alpine3.23 on arm32v6, arm32v7, i386, and ppc64le 🤔
In file included from ./Include/internal/pycore_mmap.h:16,
from Objects/obmalloc.c:5:
/usr/include/sys/prctl.h:88:8: error: redefinition of 'struct prctl_mm_map'
88 | struct prctl_mm_map {
| ^~~~~~~~~~~~
In file included from ./Include/internal/pycore_mmap.h:15:
/usr/include/linux/prctl.h:134:8: note: originally defined here
134 | struct prctl_mm_map {
| ^~~~~~~~~~~~yosifkit commented on Apr 8, 2026 I'm still able to reproduce the issue on Python 3.15.0a4 through 3.15.0a8. The fix was applied to a6, a7, and a8, but it doesn't seem to be working since the failure is still happening.
In file included from ./Include/internal/pycore_mmap.h:16,
from Objects/obmalloc.c:5:
/usr/include/sys/prctl.h:88:8: error: redefinition of 'struct prctl_mm_map'
88 | struct prctl_mm_map {
| ^~~~~~~~~~~~
In file included from ./Include/internal/pycore_mmap.h:15:
/usr/include/linux/prctl.h:134:8: note: originally defined here
134 | struct prctl_mm_map {
| ^~~~~~~~~~~~vstinner commented on Apr 8, 2026
The fix was applied to a6, a7, and a8, but it doesn't seem to be working since the failure is still happening.
The fix uses $ac_cv_libc variable in configure.ac but this variable is unset: #143730 (comment). tianon commented on Jul 10, 2026 yosifkit commented on Jul 10, 2026 Yes, the current python 3.15.0b3 (and every version newer than 3.15.0a2) still fail to build within an Alpine environment on arm32v6, arm32v7, i386, and ppc64le with the same error. Perhaps #148771 is the possible fix for this?
In file included from ./Include/internal/pycore_mmap.h:16,
from Objects/obmalloc.c:5:
/usr/include/sys/prctl.h:88:8: error: redefinition of 'struct prctl_mm_map'
88 | struct prctl_mm_map {
| ^~~~~~~~~~~~
In file included from ./Include/internal/pycore_mmap.h:15:
/usr/include/linux/prctl.h:134:8: note: originally defined here
134 | struct prctl_mm_map {
| ^~~~~~~~~~~~vstinner commented on Jul 10, 2026 yosifkit commented on Aug 13, 2026 Just an update that the latest python versions, 3.15.0rc2, 3.15.0rc1, and 3.15.0b4, also fail to build within an Alpine environment on arm32v6, arm32v7, i386, and ppc64le with the same error.
In file included from ./Include/internal/pycore_mmap.h:16,
from Objects/obmalloc.c:5:
/usr/include/sys/prctl.h:88:8: error: redefinition of 'struct prctl_mm_map'
88 | struct prctl_mm_map {
| ^~~~~~~~~~~~
In file included from ./Include/internal/pycore_mmap.h:15:
/usr/include/linux/prctl.h:134:8: note: originally defined here
134 | struct prctl_mm_map {
| ^~~~~~~~~~~~vstinner commented on Aug 14, 2026 changed the title [-]failure building Python 3.15.0a3 on Alpine[/-] [+]failure building Python 3.15.0a3 through 3.15.0 release on Alpine[/+] on Oct 13, 2026yosifkit commented on Oct 13, 2026 Just an update that this is still a problem with the 3.15.0 GA release. It fails to build within an Alpine environment on arm32v6, arm32v7, i386, and ppc64le with the same error. A fix is available in #148771.
In file included from ./Include/internal/pycore_mmap.h:16,
from Objects/obmalloc.c:5:
/usr/include/sys/prctl.h:88:8: error: redefinition of 'struct prctl_mm_map'
88 | struct prctl_mm_map {
| ^~~~~~~~~~~~
In file included from ./Include/internal/pycore_mmap.h:15:
/usr/include/linux/prctl.h:134:8: note: originally defined here
134 | struct prctl_mm_map {
| ^~~~~~~~~~~~
make: *** [Makefile:3423: Objects/obmalloc.o] Error 1serhiy-storchaka commented on Oct 20, 2026 The guard added in gh-143730 never takes effect: it tests $ac_cv_libc, which is not set anywhere in configure.ac, so AC_CHECK_DECLS([PR_SET_VMA_ANON_NAME]) always runs.
That is also what "certain architectures" comes down to. On x86_64 musl the conftest fails to compile by itself, so the macro stays undefined and the build works by accident. On i686 musl it compiles: uint64_t and __u64 are both unsigned long long there, and C23 tag compatibility allows the two identical definitions, since conftests use gcc's default -std=gnu23. The macro is then defined and the build fails, because CPython compiles with -std=c11, where the redefinition is an error.
Workaround: ./configure ac_cv_have_decl_PR_SET_VMA_ANON_NAME=no.
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