bug#75893: texlive: kpathsea doesn't use ls-R database

[vicvbcun]

On 2025-01-30T23:27:29+0100, vicvbcun wrote
> [...]
> > > The comment above the substitution says that the !! construct wouldn't 
> > > work for texlive-build-system or when building profiles.  I don't know 
> > > if it would be possible to work around this but perhaps it could be 
> > > possible to work around this if installed in profile (or environment)?
> >
> > I don’t understand what you want to install in a profile. The ls-R file
> > is already built during profile generation. See "guix/profiles.scm".
> What I meant was that we could maybe use a horrible hack like somehow 
> overwriting texmf.cnf or wrapping the engines — anything to avoid 
> rebuilding the world.  But on a second thought, LaTeX should mostly be 
> a build time dependency so that grafting with a version capable of 
> handling both the build environment and being installed should work 
> well, right?  At least until the next TeX Live release.
Actually, on a third thought, the following cursed approach might work: 
Create a variant `texlive-libkpathsea/ls-R-authoritative' of 
`texlive-libkpathsea' with the only difference being !! in front of 
$TEXMFDIST in texmf.cnf and register it as a replacement for 
`texlive-libkpathsea'.  That way packages are built with the original, 
ungrafted version but when a user installs TeX Live packages they get 
the version for which the ls-R database is authoritative.

An issue with this would be that ungexp'ing a texlive-* package 
referencing `texlive-libkpathsea' should yield the grafted version so 
the profile hook would probably need to be changed.

vicvbcun