Ability to specify per_file_copt for external repositories

[rohitsaboo]

I want to be able to add the following to my .bazelrc in order to silence unused parameter warnings from protobufs. However, per_file_copt does not seem to work with the leading @ to identify other repositories.
--per_file_copt=@com_google_protobuf//.*,@com_google_protobuf//.*@-Wnounused-parameter

(Of course other personally less appealing alternatives include setting -Wnounused-parameter for everything or going inside the protobuf repo and cleaning up the hundred or so warnings.)

[nicolov]

--per_file_copt=external/reponame/.*\.cc@-myflag seems to work for me.

[thymbahutymba]

I would like to apply the flag for everything except all external deps which are out of my control but it does not seems to work. I've inserted in the .bazelrc the following line:
build --per_file_copt=-external/.*@-Werror=unused-variable. If instead I use package specific name it works just for such dep build --per_file_copt=-<package name>/.*@-Werror=unused-variable. How can I solve this?

Edit:
I also wish that this error would not be throuwn wheter the external heder is included somewhere in the code. This issue seems to appear using the second version of what I wrote before.

[sgowroji]

Hi there! We're doing a clean up of old issues and will be closing this one. Please reopen (or ping me to reopen) if you’d like to discuss anything further. We’ll respond as soon as we have the bandwidth/resources to do so.

[vittorioromeo]

@sgowroji: I would like this to be re-opened, as I need this feature to suppress external dependency warnings.

[fmeum]

@vittorioromeo Bazel now has an external_include_paths feature that can silence these warnings. Do you need them to be silenced selectively?

[vittorioromeo]

@vittorioromeo Bazel now has an external_include_paths feature that can silence these warnings. Do you need them to be silenced selectively?

That doesn't work for me.

For example, I just updated abseil-cpp:

bazel_dep(name = "abseil-cpp", version = "20260107.0")

And now some other bazel_dep dependencies that depend on Abseil end up creating a lot of deprecation warnings while they're getting compiled, even with external_include_paths.

I would like to pass -w to the compilation of my bazel_dep dependencies, as I don't really care about those.