Setting environment variable for builds triggered by pex

[jberkel]

Is there a way to set environment variables to the process that builds the packages? I'm using pex_binary from pants, and I'd like to skip building an extension for a package which requires setting NO_SQLITE=1 in the environment. The build is sandboxed, so I'd need to pass this through with a command-line argument I imagine.

[jsirois]

@jberkel this is a Pants question. Pex does not block env vars. You should know, as a Pants user, that Pants does two important things behind your back:

1. It does not operate directly on your source files in general. It copies a subset of them to a sandbox directory and operates there.
2. It scrubs environment variables in general and you must read docs and struggle generally to punch env var holes.

Sounds like you're fighting case 2. Good luck!

[jberkel]

Alright, pex on its own doesn't do any sandboxing then? It's just the pants sandbox you mean?

[jsirois]

Correct - all the sneakiness is Pants. Pex is straightforward and not sneaky. FWIW, I think you want this: https://www.pantsbuild.org/2.29/reference/subsystems/subprocess-environment

[jsirois]

But, @jberkel please go yell at Pants maintainers a little or else chip in and make things better somehow over there. This stuff confuses more people than just you.