[core-updates-frozen] Different variants of Python packages in the same profile?

[Ricardo Wurmus <rekado@elephly.net>]

Hi Guix,

on the core-updates-frozen branch we have a minor problem: 
python-numpy has been upgraded to 1.21, but python-numba can only 
be built with 1.20[1].  I added python-numpy-1.20 and made 
python-numba use it.

Now the problem I have is that numba is used with other packages 
(such as python-scikit-learn) that build with the latest numpy. 
An example is python-umap-learn, which propagates both 
python-numba (with python-numpy-1.20) and python-scikit-learn 
(with python-numpy).  This doesn’t work because Python only knows 
about the name “numpy” and will pick the first matching module on 
the load path.

So… since numpy 1.20 is the exception here, could we perhaps … 
rename it?  And then have python-numba import that renamed module 
“totally-not-numpy” instead of “numpy”?  Could we thus avoid this 
conflict?  If renaming is an option — how would it be done?  Is it 
enough to rename the “numpy” directory with “numpy-1.20”, the 
“numpy.py” file with “numpy-1.20.py”, and then update all “import” 
statements both by numpy itself and by python-numba?

I’d like to fix this before merging core-updates-frozen, as this 
affects at least 16 bioinformatics packages and working around 
this will be difficult for users.

-- 
Ricardo

[1]: https://github.com/numba/numba/issues/7176