AppEnv: non-reproducable EnvironmentError

[sweh]

Got this error once, next deploy run succeeded:

<host> > SMTPBackend > AppEnv('40ee344c') > LockedRequirements
ERROR: .appenv/40ee344cc81b5ed5384b00b10831686bcf5fa36925edd0a560c2dc9cdf99ca3e/bin/python -m pip install --no-deps -r .appenv/40ee344cc81b5ed5384b00b10831686bcf5fa36925edd0a560c2dc9cdf99ca3e/requirements.lock
Return code: 1
STDOUT
Looking in indexes: https://pypi.org/simple, https://pypi:****@<custompypi>/simple
Collecting Babel==2.7.0
  Using cached Babel-2.7.0-py2.py3-none-any.whl (8.4 MB)
Collecting Beaker
  Using cached Beaker-1.11.0.tar.gz (40 kB)
Collecting Chameleon==3.4
  Using cached Chameleon-3.4.tar.gz (116 kB)
Collecting IP2Location
  Using cached IP2Location-8.4.1-py3-none-any.whl (6.9 kB)
Collecting Mako==1.1.2
  Using cached Mako-1.1.2-py2.py3-none-any.whl (75 kB)
Collecting MarkupSafe==1.1.1
  Using cached MarkupSafe-1.1.1-cp36-cp36m-manylinux1_x86_64.whl (27 kB)
Collecting Paste==3.2.5
  Using cached Paste-3.2.5-py2.py3-none-any.whl (592 kB)
Collecting PasteDeploy==2.0.1
  Using cached PasteDeploy-2.0.1-py2.py3-none-any.whl (17 kB)
Collecting Pillow
  Using cached Pillow-7.1.2-cp36-cp36m-manylinux1_x86_64.whl (2.1 MB)

STDERR
ERROR: Could not install packages due to an EnvironmentError: Could not find a suitable TLS CA certificate bundle, invalid path: /path/to/.appenv/40ee344cc81b5ed5384b00b10831686bcf5fa36925edd0a560c2dc9cdf99ca3e/lib/python3.6/site-packages/pip/_vendor/certifi/cacert.pem

[ctheune]

Not sure what to do about this. Let me know if this happens again ...