not sure which variant you are running: I think (double check this) but I think freebsd has better rust support. I am working up an openbsd variant myself on an old thinkpad but I haven’t been able to compile anything important because I’ve working through pfsense and getting network routing setup correctly.
Prelim research for OBSD found semarie is working porting the rustLang but check the issues section as things are on the edge here.
wish I had more for you and I’m excited to see what you end up with