How can I pass custom environment variables to whatever creates pytest_runner.pex?

this? https://www.pantsbuild.org/2.20/docs/python/goals/test#setting-environment-variables

I think I tried that and it didn't work.

This is worth a shot. Despite being phrased like it applies generically, it is not true. (it should be) It's not applied generically so it's per call-site to respect this subsystem setting. https://www.pantsbuild.org/2.20/reference/subsystems/subprocess-environment#env_vars

Thanks @curved-television-6568!