Transitive data dependencies trigger rebuilds

[max-heller]

It appears that changes to data dependencies causes rebuilds of targets that depend on targets with the direct data dependencies. For example, a library bar with data = ["foo"] does not rebuild when foo changes, but a binary depending on bar does.

Reproduction steps using the attached repo:

1. bazel build //... to hydrate cache

2. bazel build //... --subcommands (should see no subcommands)

3. Edit data_dep.txt

4. bazel build //... --subcommands

   SUBCOMMAND: # //:bin_depending_on_lib_with_data_dep [action 'Compiling Rust bin bin_depending_on_lib_with_data_dep (1 files)', configuration: 7f8856bb0405540c89cb61a09c1d0562ac1a95a54b0f8a7e6cabe690edf58098, execution platform: @@platforms//host:host, mnemonic: Rustc]
   

data-rebuild-repro.zip (credit to @ograff)

Possibly related:

• rules_rust/rust/private/rustc.bzl

  Lines 1914 to 1917 in f9d42ff

  	out_dir_compile_inputs = depset(
  	input_files,
  	transitive = [dep_info.link_search_path_files, dep_info.transitive_data] + input_depsets,
  	)

• rules_rust/rust/private/rustc.bzl

  Lines 310 to 312 in f9d42ff

  	# Track transitive non-macro data in case a proc macro depends on this crate.
  	transitive_data.append(crate_info.data)
  	transitive_data.append(dep_info.transitive_data)

• Update cargo_build_script to work without runfiles support. #2887