test_posix fails on an android emulator running an x86 system image at API level 21.

For the first ERROR, on android we have instead of a list of group IDs:
root@generic_x86:/data/local/tmp # id -G
uid=0(root) gid=0(root) groups=1003(graphics),1004(input),1007(log),1011(adb),1015(sdcard_rw),1028(sdcard_r),3001(net_bt_admin),3002(net_bt),3003(inet),3006(net_bw_stats) context=u:r:su:s0


======================================================================
ERROR: test_getgroups (test.test_posix.PosixTester)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/sdcard/org.bitbucket.pyona/lib/python3.6/test/test_posix.py", line 815, in test_getgroups
    set([int(x) for x in groups.split()]),
  File "/sdcard/org.bitbucket.pyona/lib/python3.6/test/test_posix.py", line 815, in <listcomp>
    set([int(x) for x in groups.split()]),
ValueError: invalid literal for int() with base 10: 'uid=0(root)'

======================================================================
ERROR: test_rtld_constants (test.test_posix.PosixTester)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/sdcard/org.bitbucket.pyona/lib/python3.6/test/test_posix.py", line 1128, in test_rtld_constants
    posix.RTLD_LAZY
AttributeError: module 'posix' has no attribute 'RTLD_LAZY'

----------------------------------------------------------------------
Ran 83 tests in 0.114s

FAILED (errors=2, skipped=11)
test test_posix failed
1 test failed:
    test_posix
Total duration: 0:00:01

What RTLD_* constants exist on Android?

On Android RTLD_* constants are not defined via macros but as enum values. I guess CPython needs to check each one in configure.ac. See [1]

[1] https://android.googlesource.com/platform/bionic/+/master/libc/include/dlfcn.h

Patch attached for improved RTLD_* checking.

For test_getgroups, in Android 5.1 `id` does not support -G. [1] In Android 6.x `id` seems to support -G. [2] I guess CPython can just skip the test on Android < 6.0.

[1] https://android.googlesource.com/platform/system/core/+/android-5.1.1_r37/toolbox/id.c
[2] https://android.googlesource.com/platform/external/toybox/+/master/toys/posix/id.c

LGTM. But needed to update pyconfig.h.in and configure.

RTLD_* constants are also used in Modules/_ctypes/_ctypes.c and Python/pystate.c (this can be a cause of threading and ctypes issues on Android).

Version 2.

New changeset 811ccdee6f87 by Serhiy Storchaka in branch 'default':
Issue #26932: Fixed support of RTLD_* constants defined as enum values,
https://hg.python.org/cpython/rev/811ccdee6f87

Thank you Chi Hsuan Yen.

Please open separate issue for "id -G".

Xavier, please check that issues with ctypes and threading are not gone.

test_rtld_constants is now ok at the tip of the default branch.
Thanks Chi Hsuan Yen.
I will enter a separate issue for test_getgroups and reference it here as well as in issue #26865.

> I will enter a separate issue for test_getgroups and reference it here as well as in issue #26865.
issue #26944: android: test_posix fails.

> Xavier, please check that issues with ctypes and threading are not gone.

No ctypes still crashes and threading still hangs.