API for rewriting package fields ?

[Nicolas Graves]

Is there an interface to rewrite / update a field from a series of
packages easily?

What I get from the change in python-team last change for the
pyproject-build-system is that we need to add python-setuptools or
python-wheel to all packages that will complain about it, when trying to
build. The errors are very easy to diagnose (a string match in stderr: 
ModuleNotFoundError: No module named 'setuptools'
or
error: invalid command 'bdist_wheel'
is enough to know what's wrong).

The logical thing to do here IMO would be to have a script running,
reading stderr when it fails and programmatically replacing where it's
needed, since it's done for 2-3k packages basically.

I know some work has been done with the guix refresh command to rewrite
based on package field location, but I'm not sure it provides a
convenient-enough API to simply say in guile "add this package to
native-inputs of this package in place".

Would love some counselling here, thanks!

-- 
Best regards,
Nicolas Graves