Cargo workspaces do not support compiling two subprojects for two different targets in a single build invocation. The workaround was (still is?) to use each subproject as a standalone project just for builds. The dependency between these targets is now expressed by the Makefile invoking cargo. This also breaks IDE integrations because your IDE does not know how to ask cargo to pick the right target for each workspace member.

Bazel makes this consistent with platforms [0]. I have not used bazel with Rust but it worked fine for my multi-target C++ builds.

[0] https://bazel.build/extending/platforms