I was able to build pijul version 1.0.0-beta.9 using Guix.
You can find it in my channel —— https://git.sr.ht/~akagi/rrr

Link to the package: https://git.sr.ht/~akagi/rrr/tree/12118709e84be8b13869b4b62800c66f0e8f6f57/item/rrr/packages/pijul.scm#L336
#guix #pijul