CRUX

Hi,
python3-pip does not work if python3-setuptools is not installed. But it seems
it's impossible to successfully install python3-setuptools.

If I run 'prt-get depinst python3-setuptools',
it first installs python3-appdirs, no problem,
next python3-pyparsing, here it always throw an exception:

Found existing installation: appdirs 1.4.0
Uninstalling appdirs-1.4.0:
Exception:
...

I've configured prt-get to run pkgmk as an unprevileged user with fakeroot.
The problematic line of script is python3-pyparsing/Pkgfile:19:

/usr/bin/python3/ $SRC/get-pip.py --root=$SRC/build

get-pip.py attempts to uninstall appdirs, which is impossible.

I fixed this bug by made a simple modification to get-pip.py:

sed -i 's/"--upgrade"/"--upgrade", "--upgrade-strategy", "only-if-needed"/' $SRC/get-pip.py

By adding that option to pip inside get-pip.py, it will not try uninstalling existing dependencies if possible.
It still does not work if one has an outdated dependency, but uninstalling it should sovle the problem.

See here for the reference:
https://pip.pypa.io/en/stable/reference/pip_install/#cmdoption--upgrade-strategy