lib/extra.h file is not included in any of the source files.

Single library Mode (#159b230155fa2b14f05686d482db66db90371502)

Build logs:

• clean.build.log clean build
• commented_extra_header.build.log changed the lib/BUILD.bazel file

cc_library(
    name = "lib",
    srcs = [
        # "extra.h",
        "lib.cpp",
    ],
    hdrs = ["lib.h"],
    visibility = ["//visibility:public"],
)

• uncommented_extra_header.build.log uncommented the line from above

The above actions cause app/main.cpp to recompile, which I don't expect to happen. I suspect it due to Declared include source: lib/extra.h being used as a key for main.cpp file.

Indirection

Added slib as intermidiate library between app and lib (app -> slib -> lib).

This did not make difference lib/extra.h still shows up as change in in all three compilation units.

Change to implementation_deps

Converted lib to private dependency of slib using implementation_deps experimental feature of cc_library.

Now main.cpp does not recompile and lib/extra.h does not show up in its key. However, it still affects slib.