Invalid symbolic link ~/.cache/pex/unzipped_pexes/<hash>/.bootstrap on Fedora Silverblue/Kinoite 41

[tymonx]

The pants project uses pex and because of that it doesn't work on Linux distributions like Fedora Kinote or Silverblue (Atomic OS). Because of ~/ or /home/${USER}/ that is a symbolic link to /var/home/${USER}/. pex creates a symbolic link ~/.cache/pex/unzipped_pexes/<hash>/.bootstrap pointing to ../../../../../../var/home/${USER}/.cache/pex/bootstraps/<hash>. The main root cause is relative content of that created symbolic link. If pex file is run when current working directory is part of /home/${USER}/ then unpacking procedure fails with raised Python exception from ~/.cache/pex/unzipped_pexes/<hash>/__main__.py file:

from pex.globals import Globals

ModuleNotFoundError: No module named 'pex'

Because of invalid symbolic link added to sys.path[0] by above __main__.py file, the Python pex module cannot be found by Python interpreter.

It impacts pants: pantsbuild/pants#21799

Related issues: #2572 and #2626 Unfortunately it doesn't fix above issue for pants 2.31.1.

It looks like that fix should be fair easy to implement (using realpath).

[jsirois]

@tymonx how did you determine  #2572 and #2626 do not fix the issue. Have you verified Pants and scie-pants use versions of Pex incorporating both of those fixes?

[jsirois]

For example #2626 was only released in Pex 2.27.1 2 weeks ago: https://github.com/pex-tool/pex/releases/tag/v2.27.1

Surely the Pants folks haven't updated Pants and scie-pants to that already.

[jsirois]

@tymonx this was in fact fixed in #2626 but you need Pants 2.25.0.dev3 or newer to get that fix.

See the example docker session here: pantsbuild/pants#21799 (comment)

[jsirois]

@tymonx I'm going to close this as an answered question since pantsbuild/pants#21799 (comment) proves the fixes in #2572 and #2626 do work. You just may have to wait awhile on Pants to get a stable 2.25 release out if you're not willing to use a Pants 2.25 dev release.

[tymonx]

@jsirois You are right. It uses older version of pex 2.16.2 before fix. I will try Pants 2.25.dev3:

cat ~/.cache/pex/bootstraps/<hash>/pex/version.py

[tymonx]

@jsirois I can confirm. If fixes the issue when changing pants version to 2.25.dev3 in pants.toml file and re-running the pants command again:

[GLOBAL]
pants_version = "2.25.0.dev3"

[jsirois]

Great - thanks for confirming @tymonx.