python.path in ~/.pdm/config.toml appears to never be used

[dlukes]

Is your feature request related to a problem? Please describe.

I was trying to set a Python version for PDM to prioritize instead of the default sorting algorithm. I thought pdm config python.path /path/to/python looked promising, but it didn't work.

On closer inspection, it looks like python.path in ~/.pdm/config.toml will never be used for anything, because:

• local project settings always override global ones
• when there's no local (project-specific) .pdm.toml, it gets created first and always contains at least python.path

Being able to set a value that's never used for anything is confusing for users.

Describe the solution you'd like

I can see different solutions:

1. Add a caveat to the docs, saying that while python.path can be set in the global config, it has no effect.
2. Print a warning saying the same thing when setting python.path in the global config.
3. Implement the behavior I originally expected: when python.path exists in ~/.pdm/config.toml, bump it to the first place in the list of Python suggestions.