Rust host-compile fails on aarch64

Rust's host-compile is failing on aarch64

uilding bootstrap
    Finished dev [unoptimized] target(s) in 0.22s
Building stage0 library artifacts (aarch64-unknown-linux-musl) 
warning: dropping unsupported crate type `dylib` for target `aarch64-unknown-linux-musl`

warning: `std` (lib) generated 1 warning
warning: `test` (lib) generated 1 warning (1 duplicate)
    Finished release [optimized] target(s) in 0.83s
Building compiler artifacts (stage0 -> stage1)
error: cannot produce dylib for `rustc_driver v0.0.0 (/mnt/nbd/devel/openwrt/build_dir/hostpkg/rustc-1.69.0-src/compiler/rustc_driver)` as the target `aarch64-unknown-linux-musl` does not support these crate types

I'm going to see if I can switch it to static.

That said, what packages use rust? I'd rather just disable them. I also wonder why it's a host package and not in the toolchain.