[bug#45158] [PATCH] gnu: Add python-3.9.

[Ludovic Courtès]

Hi,

Tanguy Le Carrour <tanguy@bioneland.org> skribis:

> * gnu/packages/python.scm (python-3.9): New variable.
> * gnu/packages/patches/python-3.9-fix-tests.patch: New file.

Nitpick: the patch should be added to gnu/local.mk as well.

It LGTM but I have one concern: someone adding ‘python’ and (say)
‘python-itsdangerous’ to the same profile would get Python 3.9 together
with a Python 3.8 package.  Thus ‘PYTHONPATH’ would remain unset and the
user might become upset.  :-)

One way to work around that would be to rename 3.9 from ‘python’ to
‘python-next’.  That way, someone would have to explicitly install
‘python-next’ to get 3.9, and there wouldn’t be any bad surprises for
the rest of us.

WDYT?

Thanks,
Ludo’.