Your bug report

#42449: texlive: l3regex.sty not shipped with texlive-latex-l3kernel

which was filed against the guix package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to 42449@debbugs.gnu.org.

-- 
42449: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=42449
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