pipx broke after updating system Python to 3.10

[MicaelJarniac]

Describe the bug
pipx used to work well, back when Manjaro was on Python 3.9.
A couple of days ago, Manjaro updated to Python 3.10, and today I noticed pipx was no longer working correctly.

How to reproduce
I've uninstalled and reinstalled pipx with pip, did the ensurepath thing (even with --force), tried to reinstall-all, and after uninstalling pipx from pip I searched around for leftovers.

This is what happens when I try the reinstall-all:

➜  ~ pipx reinstall-all
/home/micael/.local/pipx/shared/bin/python: No module named pip
Failed to upgrade shared libraries
Traceback (most recent call last):
  File "/home/micael/.local/lib/python3.10/site-packages/pipx/shared_libs.py", line 113, in upgrade
    subprocess_post_check(upgrade_process)
  File "/home/micael/.local/lib/python3.10/site-packages/pipx/util.py", line 202, in subprocess_post_check
    raise PipxError(
pipx.util.PipxError: '/home/micael/.local/pipx/shared/bin/python -m pip --disable-pip-version-check install -q --upgrade pip setuptools wheel' failed

And this is what happens when I try to install a package (protontricks, on this example):

➜  ~ pipx install protontricks 
Fatal error from pip prevented installation. Full pip output in file:
    /home/micael/.local/pipx/logs/cmd_2022-01-04_15.01.57_pip_errors.log

Error installing protontricks.
➜  ~ cat .local/pipx/logs/cmd_2022-01-04_15.01.57_pip_errors.log 
PIP STDOUT
----------

PIP STDERR
----------
/home/micael/.local/pipx/venvs/protontricks/bin/python: No module named pip

Operating System: Manjaro Linux
KDE Plasma Version: 5.23.4
KDE Frameworks Version: 5.89.0
Qt Version: 5.15.2
Kernel Version: 5.15.12-1-MANJARO (64-bit)
Graphics Platform: X11
Processors: 4 × AMD Ryzen 3 2200G with Radeon Vega Graphics
Memory: 7.7 GiB of RAM
Graphics Processor: NVIDIA GeForce GTX 970/PCIe/SSE2

➜  ~ python --version
Python 3.10.1
➜  ~ pip --version
pip 21.3.1 from /home/micael/.local/lib/python3.10/site-packages/pip (python 3.10)
➜  ~ pipx --version
1.0.0

I did pip install --upgrade pip setuptools wheel, and that works, so I believe those packages are already up-to-date.

I did also try installing pipx as pip install --user pipx, and that didn't help.

---

Solution in comments

[dracos]

Possible dupe of #278? My fix there was to remove ~/.local/pipx/shared and then reinstall-all worked okay (though note it had already removed all my virtualenvs so I can't say if they'd then upgrade okay).

[MicaelJarniac]

That helped me solve it, thanks!

What I did was to first use pyenv to reinstall Python 3.9 and set it as global, then use its pip to uninstall the old version of pipx.

After that, I used pyenv to set Python back to system, and uninstalled the new pipx from there too.

I then removed ~/.local/pipx (I did the entire folder just to be sure), then I installed pipx again, and now it's working!

[A1vinSmith]

It happens again on Python 3.11.1

dracos comment still working for it.