The rust-compiled packages (for example aardvark-dns and ripgrep) are failing to build in master. They aren't being linked against libc, and are failing on unmet dependencies for libc functions. fstat64, lseek64, etc etc.
Whoever let rust into this party, anyway. Sheesh. 
I've been waiting for rust support to become solid enough that we can build Suricata. Then we can pit it against snort in a death match, one left standing.
While trying to add a custom Rust package I got stuck with the same missing references errors. I was able to reproduce the same issue on Rust packages already part of the OpenWRT distribution (e.g. aardvark-dns).
After updating to the latest main (at time of git pull this was 598e058080b990cf59ff84d3d50b639f44f11614), I no longer see these errors and at least aardvark-dns compiles fine 
Great! I'll take a look again, thanks!