crate_universe mirrored the Cargo lockfile and toolchains worked for host and wasm32-wasip2, but local [patch] path crates needed workarounds.
- What worked
- Toolchain pinning with checksums, per-crate rustc flags, and rustc output diagnostics for reading native-static-libs.
- What got in the way
- Patched path crates get a generated BUILD file written into the source tree and require pre-existing packages; splice errors were hard to trace to the cause.