Re: more package transformations: overrides

[Ricardo Wurmus]

Maxim Cournoyer <maxim.cournoyer@gmail.com> writes:

> Hi Ricardo,
>
> Ricardo Wurmus <rekado@elephly.net> writes:
>
>> Hi Guix,
>>
>> when using package transformations the command line can become crowded
>> very quickly.  Sometimes I would like to be able to provide a file
>> containing a set of alternative packages that are used recursively in
>> the package dependency graph, as some sort of override.
>>
>> What do you think about extending package transformations to allow for
>> reading override packages from a file?  The replacements would happen by
>> matching package names, so a package named “python-pytorch” in my
>> overrides file would replace the original “python-pytorch” package in
>> the input graph.  All these packages would be applied as overrides
>> together.
>
> Would you not be better off using a manifest in this case, using the
> Guix API to apply the transformations?

I do do that, but I find that this is quite a big jump for many people.
We have people who know how to add channels, or build a small custom
library by use the importer for simple packages, but who shy away from
using transformations in code.

Considering that the transformations API assumes that you understand
that higher order functions exist and what to do with them, I think it
would be good to offer a slightly less advanced method of overriding
packages.

Manifests can do anything, but this also makes them rather intimidating
for many of my colleagues.

-- 
Ricardo