Subject: Re: [bug#77708] [PATCH] gexp: ‘with-parameters‘ is respected by caches.

From: David Elsing <[email-masked]>
Date: Sun, 06 Jul 2025 16:15:01 +0000

Hi,

Ludovic Courtès <[email-masked]> writes:

> Oh, I see.  The GSoC project you’re referring to was very nice but IMO
> went a bit too far in terms of what it provides; but the main factor for
> it being discontinued is that the intern walked away after the
> internship I believe, and nobody picked it up.  FWIW, I was advocating
> for something simpler and that would try to reduce the risks of
> combinatorial explosion¹.

Ah ok, that makes sense. Would it be possible for multiple packages to
share the same parameter, so that it can be set for all dependencies of
a package? I guess it should be doable with `package-mapping'.
I'm also not sure the full Cartesial product of all possible parameters
should always need to be supported, as it might or some combinations
don't make sense, so I think there should be a way to specify the
supported combinations (which isn't the case for both proposals IIUC).

> At any rate, I don’t think parameters (in the sense of SRFI-39) can be a
> useful building block for parameterized packages (in the sense of Gentoo
> USE flags.)  I think parameterized packages need to be implemented with
> some declarative interface as was proposed during that GSoC project and
> that earlier message I mentioned.

Yes I agree that using SRFI-39 parameters is not very suitable for
parameterized packages. My idea was just to fix `with-parameters' until
parameterized packages are implemented properly, but it makes sense if
you don't want to support and later deprecate this.
Maybe `with-parameters' and `<parameterized>' should be renamed if they
only support `%graft?', `%current-system' and `%current-target-system'?

Thanks,
David