A need to download pijul source code from nix created a non-working fetchPijul 1. Deleting the .pijul would get the source, but would be heavy on nest. Archives would be great quick-solution for now, and would probably be useful to others. Are archives served already?

Not yet. The head of channels could easily be served. Archives for tags could also be pretty cheap.

Interesting to see fetchPijul being developed on GitHub ;-)