cargo-bazel: fix binary targets of proc-macro crates using wrong dep attribute#3975
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UebelAndre merged 2 commits intobazelbuild:mainfrom Apr 17, 2026
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…attribute Problem: When a crate has both a rust_proc_macro library target and rust_binary targets (e.g. development utilities shipped alongside the proc-macro), make_rust_binary unconditionally places the library in `deps`. However, rules_rust validates that proc-macro libraries must appear in `proc_macro_deps`, not `deps`. This causes analysis failures for any such crate. Solution: In make_rust_binary, detect whether the crate's library target is a proc-macro by checking if Rule::ProcMacro(_) is present in krate.targets. If it is, insert the library label into proc_macro_deps instead of deps. Testing: - binary_of_proc_macro_crate_uses_proc_macro_deps: verifies that the generated rust_binary has the proc-macro lib in proc_macro_deps and not in deps.
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Problem
When a crate has both a
rust_proc_macrolibrary target andrust_binarytargets (e.g. development utilities shipped alongside the proc-macro),make_rust_binaryunconditionally places the library indeps. However, rules_rust validates that proc-macro libraries must appear inproc_macro_deps, notdeps. This causes analysis failures for any such crate.Solution
In
make_rust_binary, detect whether the crate's library target is a proc-macro by checking ifRule::ProcMacro(_)is present inkrate.targets. If it is, insert the library label intoproc_macro_depsinstead ofdeps.Testing
binary_of_proc_macro_crate_uses_proc_macro_deps: verifies that the generatedrust_binaryhas theproc-macro lib inproc_macro_depsand not indeps.