Re: Using an alternative python to build python modules

[Edouard Klein <edou@rdklein.fr>]

As an example in this line of thought, a long time ago I submitted a
patch (since then reverted as it broke a lot of things) to use an
obsolete version of a python module, which was the only one that worked
with a specific module that hadn't updated its dependencies:

https://git.savannah.gnu.org/cgit/guix.git/commit/?id=32ba87c14fd5e5b54d95211cd9a159d568ce7c67

Look at the following lines:

#+begin_src scheme
(define-public prompt-toolkit-2-instead-of-prompt-toolkit
  (package-input-rewriting/spec
   `(("python-prompt-toolkit" . ,(const python-prompt-toolkit-2)))))
#+end_src

If instead of replacing "python-prompt-toolkit" with
python-prompt-toolkit-2, you could replace "python" with the version of
python you want to use, package-input-rewriting would then handle the
work of changing the python package anywhere it appears in any
dependency of your manifest.

You can then end your manifest with
(python-3.6-instead-of-python python-apted)

Cheers,

Edouard.


Wojtek Kosior via <help-guix@gnu.org> writes:

> [[PGP Signed Part:Undecided]]
> Hi Kyle,
>
> Have you looked at the (package-input-rewriting) procedure described
> towards the bottom of "Defining Package Variants"[1]?
>
> You might also like to look at the not-exported
> (package-with-explicit-python) proc defined in
> guix/build-system/python.scm[2]. It is used to produce python2 variants
> of packages but I suppose it would also work for swapping the minor
> versions of python3.
>
> Good luck with your task :)
>
> Wojtek
>
> [1] https://guix.gnu.org/manual/en/html_node/Defining-Package-Variants.html
> [2] https://git.savannah.gnu.org/cgit/guix.git/tree/guix/build-system/python.scm?id=b544f460989a6189af111bb3ff6752cabdf23abc#n82
>
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>
> On Fri, 17 Feb 2023 21:27:39 +0000
> Kyle Andrews <kyle@posteo.net> wrote:
>
>> Dear Guix,
>>
>> I want to use the python-apted package in my manifest. That package is
>> not in Guix, but can readily be fetched from:
>>
>> ```
>> guix import pypi APTED > python-apted.scm
>> ```
>>
>> I just had to prefix the following modules to turn that into a package
>> definition as well as a manifest.
>>
>> ```
>> (use-modules (guix packages)
>> 	     (guix download)
>> 	     (guix licenses)
>> 	     (guix profiles)
>> 	     (gnu packages)
>> 	     (guix build-system python))
>> ```
>>
>> During my original testing of my scientific workflow I discovered that
>> there was a bug introduced to the APTED package which was caused by a
>> change in how python worked under the hood. As a result, the APTED
>> package only advertises compatibility with python versions less than
>> 3.7. So, I would like to use python 3.6 to be on the safe side.
>>
>> I also want to include 60+ other packages in my manifest which are
>> "current" with the Guix repository and included within it. For
>> situations like this it would be really convenient if it were possible
>> to pass a version of python to python-build-system. Then, I hope all I
>> would have to do is pass another another defined variant of the python
>> package (e.g. called python-3.6) into that build-system argument.
>>
>> For example:
>>
>> ```
>> (build-system python-build-system #:python python-3.6)
>> ```
>>
>> That would be quite convenient and in line with the level of complexity
>> I was faced with when I took the conda approach before trying to use
>> Guix. Unfortunately, this functionality doesn't seem to be provided out
>> of box and I am seeking help in the hopes that there is an easy way to
>> do it.
>>
>> Am I thinking about this right?
>>
>> Thanks,
>> Kyle
>>
>> P.S.
>>
>> APTED claims to also be able to run on top of python-2.7 so maybe that
>> fact could be used to simplify this specific issue. I just wanted to
>> discuss the general problem first because I really want Guix to gain
>> broad traction within the scientific community.
>>
>> P.P.S.
>>
>> Here is a pretend manifest where I would love guidance on how to make
>> python-apted get built in the context of python-2.7 or ideally
>> python-3.6 even though the latest version of python is python-3.9 (where
>> APTED doesn't always work).
>>
>> ```
>> (use-modules (guix packages)
>> 	     (guix download)
>> 	     (guix licenses)
>> 	     (guix profiles)
>> 	     (gnu packages)
>> 	     (guix build-system python))
>>
>> (define-public python-apted
>>   (package
>>     (name "python-apted")
>>     (version "1.0.3")
>>     (source (origin
>>               (method url-fetch)
>>               (uri (pypi-uri "apted" version))
>>               (sha256
>>                (base32
>> 		"1sawf6s5c64fgnliwy5w5yxliq2fc215m6alisl7yiflwa0m3ymy"))))
>>     (build-system python-build-system)
>>     (arguments '(#:tests? #f))
>>     (home-page "https://github.com/JoaoFelipe/apted")
>>     (synopsis "APTED algorithm for the Tree Edit Distance")
>>     (description "APTED algorithm for the Tree Edit Distance")
>>     (license expat)))
>>
>> (concatenate-manifests
>>  (list (specifications->manifest (list "r" "r-dplyr" "r-reticulate"))
>>        (packages->manifest (list python-apted))))
>> ```
>>
>
>
> [[End of PGP Signed Part]]