bug#51252: [core-updates-frozen] lualatex needs additional setup

[John Kehayias]

Hello,

This is my first time trying out TeX on Guix, but ran into a problem trying to 
run lualatex on core-updates-frozen. Since I wasn't sure what I needed, I tried 
the huge full texlive package in case that solved the problem I was seeing. It 
did not.

Running lualatex on anything gives the output

This is LuaTeX, Version 1.13.0 (TeX Live 2021/GNU Guix)
 restricted system commands enabled.

kpathsea: Running mktexfmt lualatex.fmt
/gnu/store/cpflshy9z2yzd8dybm0j9a7i0bscpxa2-texlive-bin-20210325/share/texmf-dist/scripts/texlive/fmtutil.pl:
 Unexpected non-option argument(s): lualatex.fmt
Try "fmtutil --help" for more information.
I can't find the format file `lualatex.fmt'!

xelatex on the same file and environment worked fine. After some digging, I 
could get the lualatex.fmt file by installing texlive-tex-ini-files and running

lualatex -ini 
/gnu/store/skznnf2n2f4dwg44gm8bvcn78157z69p-texlive-tex-ini-files-59745/share/texmf-dist/tex/generic/tex-ini-files/lualatex.ini

With this lualatex.fmt file present, lualatex runs and produces the correct 
output. I'm guessing this is not the expected procedure, though I haven't been 
able to test on master to compare yet. I wasn't sure if I missed a texlive- 
package, but xelatex working as is makes me think not.

John