Missing dependencies for package `forest`, `environ`

[Zdenek Wagner]

po 11. 1. 2021 v 0:38 odesílatel G. Cassian Alexandru
<g.cassian.alexandru at posteo.eu> napsal:
>
> Missed one, `tikz` (so pgf).
>
> And `environ`, one of its dependencies, has an undeclared dependency on
> `trimspaces`.
>
> Maybe it would be an idea to go through the ctan database some time and
> just find all uses of `RequirePackage` to semi-automatically improve
> this situation?
>
This would not be so difficult, I always install scheme-full hence
making such a script is a matter of minutes. However, it would create
too many dependencies. For instance, my zwpagelayout needs color only
conditionally. If you do not prepare crop marks in color, the package
is not loaded. A few packages are loaded only if they are already
installed and zwpagelayout then offers additional functionality, if
they are not found, some functionality is disabled. It also matters
whether the package is used with xelatex, pdflatex, or latex with
dvips. It makes no sense to require pdflatex-support packages if a
user wants xelatex only. There may be more such packages.

This leads me to a question. There are hard dependencies (needed
always) and soft dependencies (needed if a special functionality is
requested). Is there a conditional dependency? For instance, hard
dependency for use in xelatex but not needed at all with other
engines.

Zdeněk Wagner
http://ttsm.icpf.cas.cz/team/wagner.shtml
http://icebearsoft.euweb.cz