I have tried to build the rust library on OBS, but failed.
Rust in SFOS5 is too old for at least 3 of the dependent crates, and cargo is too old to read the latest version’s config (1.160.0, the previous version doesn’t have that problem).
If any of the local rust people have a newer compiler available, here’s what I have so far:
https://build.sailfishos.org/package/show/home:nephros:devel:email/deltachat-core