Required packages can be seen with:
$ rg RequirePackage $(guix build texlive-datetime2)
* gnu/packages/tex.scm (texlive-datetime2)[propagated-inputs]: Add
TEXLIVE-ETOOLBOX, TEXLIVE-LATEX-XKEYVAL, and TEXLIVE-TRACKLANG.
Signed-off-by: Nicolas Goaziou <mail@nicolasgoaziou.fr>