How to make tectonic use a modern moderncv version

[igalic]

Hi folks,

I'm using tectonic and pandoc to build my CV(s) but I cannot make tectonic use the correct moderncv version.
https://codeberg.org/meena-co/cv has a minimal repro:
make SOURCE=resume-repro takes my resume.pandoc.tex and applies resume-repro.md to build a PDF and demonstrate that tectonic is using a moderncv version old enough to not have Codeberg and Mastodon, and is also ignoring the one I provide as submodule.

What am I doing wrong here?
I can't seem to find any reference to moderncv in tectonic's source, so where is the version pinning coming from?

\ProvidesClass{moderncv}[2022-02-21 v2.3.1 modern curriculum vitae and letter document class]

[igalic]

okay, so, this is, in effect, related to #685
I need to create a newer bundle that replaces what the 4 year old one.

another issue might be that tectonic ignores TEXINPUTS by default. (anything other than ., that is)