#2066 Intermittent / nondeterministic failure building `requirements.pex` due to missing `site-packages` Issue created by danxmoran Our CI will occasionally fail with an error like:

Traceback (most recent call last):
  File "/home/color/.cache/nce/99421dee8fedc336d5a6bb8322fbfa602bc68fe63303ae702ec7b9c5672cd086/bindings/venvs/2.15.0rc6/lib/python3.9/site-packages/pants/engine/process.py", line 289, in fallible_to_exec_result_or_raise
    raise ProcessExecutionFailure(
pants.engine.process.ProcessExecutionFailure: Process 'Building 1 requirement for requirements.pex from the 3rdparty/lockfiles/resolves/pants-plugins.lockfile resolve: pantsbuild.pants<2.16,>=2.15.0a0' failed with exit code 1.
stdout:

stderr:
The virtualenv at /tmp/pants/named_caches/pex_root/venvs/4c85013f478e0393bbf8db8fcf02e1def7ff5031/ba7a55164c2afb363895254bbb1063124dd74d5b.lck.work is not valid. No site-packages directory was found in its sys.path:
/opt/python/3.9.16/lib/python39.zip
/opt/python/3.9.16/lib/python3.9
/opt/python/3.9.16/lib/python3.9/lib-dynload
/opt/python/3.9.16/lib/python3.9/site-packages

We've seen it hit across different resolves, Python interpreter versions, and Pex versions - the error above happened on Pex

v2.1.122

. It happens very infrequently (once every few weeks). I captured the Pants caches & execution dir for the error above. The archive is too big to attach via GitHub, but I can share it via Slack / GDrive upload. pantsbuild/pex