Chris Jerdonek

Hi Neal! Yes, I know it works, but I don't have recent experience installing it on Ubuntu via `python3-venv`. In my own environments, I'm currently installing Python from source rather...

Ah, cool, glad you figured it out so quickly! (Btw, I misunderstood the "unable to locate" error as being unable to locate the package after installation, but now I see...

Thanks for the review, @nealmcb! I've updated the PR to address your comments.

The "reversal" in meaning of the environment variables doesn't seem to affect all of the environment variables, as the title of this issue suggests. I believe only `PIP_NO_CACHE_DIR` and `PIP_NO_BUILD_ISOLATION`...

I proposed a PR for this issue (the `PIP_NO_CACHE_DIR` half) here: https://github.com/pypa/pip/pull/5884

PR #5884 fixed this for the `PIP_NO_CACHE_DIR` variable. `PIP_NO_BUILD_ISOLATION` is still unaddressed, though, I believe.