Segmentation fault during pip install on python3.6

[Matt Riedemann]

This is rare and intermittent but seen on grenade and devstack jobs, e.g.:

http://logs.openstack.org/02/570202/8/check/grenade-py3/1625f50/logs/grenade.sh.txt.gz#_2019-04-16_18_13_00_689

2019-04-16 18:12:59.551 | Installing collected packages: WebOb, pytz, Babel, oslo.i18n, wrapt, debtcollector, oslo.context, msgpack, netaddr, netifaces, iso8601, oslo.utils, oslo.serialization, rfc3986, oslo.config, pycadf, pyinotify, monotonic, python-dateutil, oslo.log, os-service-types, keystoneauth1, python-keystoneclient, decorator, dogpile.cache, oslo.cache, keystonemiddleware
2019-04-16 18:13:00.689 | /opt/stack/old/devstack/inc/python: line 212: 11877 Segmentation fault $sudo_pip http_proxy="${http_proxy:-}" https_proxy="${https_proxy:-}" no_proxy="${no_proxy:-}" PIP_FIND_LINKS=$PIP_FIND_LINKS SETUPTOOLS_SYS_PATH_TECHNIQUE=rewrite $cmd_pip $upgrade $install_test_reqs $@

And from the syslog:

Apr 16 18:13:00 ubuntu-bionic-ovh-gra1-0005153120 kernel: pip3.6[11878]: segfault at 7f973189a000 ip 00000000004e8620 sp 00007ffc4b1c0370 error 4 in python3.6[400000+3b2000]

http://logstash.openstack.org/#dashboard/file/logstash.json?query=message%3A%5C%22Segmentation%20fault%5C%22%20AND%20message%3A%5C%22%24cmd_pip%20%24upgrade%20%24install_test_reqs%5C%22%20AND%20tags%3A%5C%22console%5C%22&from=7d