This looks similar to some Bazel rules I'm working on. I'm also using the approach of defining target environments up front [1], but the main difference is that

This looks similar to some Bazel rules I'm working on. I'm also using the approach of defining target environments up front [1], but the main difference is that I'm currently offloading the actual resolution process to Poetry or PDM, which both generate cross-platform lock files. But Poetry and PDM don't add build dependencies to lock files - which I need - so I'm thinking of building a custom resolver. Did you consider using resolvelib [2], which is what underlies both pip and PDM? [1] https://github.com/jvolkman/rules_pycross/blob/main/examples/poetry/BUILD.bazel#L58-L71 https://github.com/jvolkman/rules_pycross/blob/main/examples... [2] https://github.com/sarugaku/resolvelib https://github.com/sarugaku/resolvelib