> Yes, it must be something in the chroot, because when run in the plain command line, all tests as well on openSUSE Tumbleweed (with the latest updates).

Are you testing with patches? It may be interesting to try to get these patches upstream:

[   59s] Patch #1 (Python-3.0b1-record-rpm.patch):
[   59s] Patch #2 (python-3.6.0-multilib-new.patch):
[   59s] Patch #4 (python-3.3.0b1-localpath.patch):
[   59s] Patch #6 (python-3.3.0b1-fix_date_time_compiler.patch):
[   59s] Patch #7 (python-3.3.0b1-curses-panel.patch):
[   59s] Patch #9 (python-3.3.0b1-test-posix_fadvise.patch):
[   59s] Patch #12 (python-3.3.3-skip-distutils-test_sysconfig_module.patch):
[   59s] Patch #15 (subprocess-raise-timeout.patch):
[   59s] Patch #22 (distutils-reproducible-compile.patch):

Some patches seem old. Are they still needed? Where can I find these patches? I'm interested by patches modifying site.py for example.