users to host git repos and present them over gopher and gemini using this program.

i like it already

I forgot to add though that I only managed to test it on x86_64, as the i686 package for libgit2 is seemingly stuck at 1:1.4.3-1 when the repos indicate somehow that 1:1.4.4-1 is the latest version and thus the download 404s and the build fails.

according to the web interface, libgit2 for i686 is 1:1.4.3-1.0, and that package is in the repos - libgit2 1:1.4.4-1 for i686 is also available; but it is in staging - i can only guess that you edited the pacman.conf in the i686 chroot to enable/disable the staging repo, and forgot to run pacman -Syyuu in the chroot - librechroot/libremakepkg will not do that automatically

No matter what I do, the i686 build still fails when trying to fetch 'libgit2-1:1.3.0-1.0-i686.pkg.tar.zst' (it just 404s).

i dont have any such problem - the chroots do get borked occasionally

you can try to clean it properly

# librechroot -n <CHROOT_NAME> clean-repo
# librechroot -n <CHROOT_NAME> update
# librechroot -n <CHROOT_NAME> clean-pkgs

if that does not work, just nuke the chroot and make a new one

# rm -rf /var/lib/archbuild/<CHROOT_NAME>
# librechroot -A i686 -n <CHROOT_NAME> make

(intentionally not regular web stagit, because cgit does a better job there)

why not package the web server also? - cgit is not doing a great
job for parabola - it is extremely slow and CPU intensive for
some reason - i could probably find what that reason is, and
correct it; but maybe this one is more light-weight than cgit

is the web server built from the same sources?
is there a demo of it somewhere?

Here's an example of web stagit, https://codemadness.org/git/

Is there any need for this still?

There is another option: gemnigit, just got a reply from the author affirming that this is the license for the whole project:
https://git.sr.ht/~kornellapacz/gmnigit/tree/master/item/LICENSE