Re: [PATCH 2/2] gnu: Remove ghc-parsec, ghc-stm, ghc-text, ghc-xhtml.

[Ricardo Wurmus]

Hi Robert,

> I’ve just updated and rebundled them to fix the haskell packages
> that were added to Guix in the meantime (original patch from Jun 1:
> https://debbugs.gnu.org/cgi/bugreport.cgi?bug=36038).

thank you for these patches.  They look good to me.  I’ll apply them in
a moment.

> Consensus last time this was discussed was that we should implicitly
> depend on the GHC-included packages instead of re-packaging them:
>
> https://lists.gnu.org/archive/html/guix-patches/2019-06/msg00000.html

I’m having second thoughts about this consensus, because I remembered
what I did for R.  R comes with a bunch of “recommended packages” and
they are required to run the test suite.  But instead of having the R
package include all of these “recommended packages” I created
“r-minimal” and one package for each of these otherwise included
modules.

In R applications and libraries I added packages as needed, even if they
were part of the “recommended packages”.  This was possible because we
used “r-minimal” in the build system.

Is something like this at all possible for GHC?  Can we force GHC to
ignore modules it includes or remove them all together?  It would be
more elegant if Guix packages for Haskell applications each had a
comprehensive “inputs” field without having to rely on any implicitly
included libraries.

--
Ricardo