#2222 Pex passes `--use-feature 2020-resolver` to all versions of Pip for Python 2. Issue created by jsirois This is a bug since Pip dropped support for naming this feature (because they made it the default) in 22.3: https://pip.pypa.io/en/stable/news/#v22-3 The resulting error is:

option --use-feature: invalid choice: '2020-resolver' (choose from 'fast-deps', 'truststore', 'no-binary-enable-wheel-cache')

pantsbuild/pex