jsmoeller pointed out that trying to build for a riscv64 platform is failing at the moment in at least librsvg.  The root cause is our backported Rust toolchain from meta-lts-mixins:kirkstone/rust-1.68 missing one small but required piece of an upstream change with respect to RISC-V that likely breaks building all Rust based packages.  This issue will track getting a fix in via meta-lts-mixins update.