Migration needed for Automatic Exec Groups

[kotlaja]

Migration to Automatic Exec Groups (AEGs) is needed since its incompatible flag (--incompatible_auto_exec_groups) will be enabled for Bazel@Head quite soon, thus it will be breaking your project. Please migrate and fix potential errors, in order to unblock your project and users who depend on your project. Potential errors can be triggered by building your project with this incompatible flag. Note that AEGs will not be flipped by default for Bazel 8, but for Bazel at head after Bazel 8 cut.

For more details, please check:

bazelbuild/bazel#19981

General Bazel documentation for AEGs

Particularly interesting parts could be

Most common errors you could see during this migration
How to disable AEGs until fully migrated
Never heard of incompatible flags before? We have documentation that explains everything.

If you have any questions, please file an issue in https://github.com/bazelbuild/bazel/issues.

[kotlaja]

Please check my changes which might be sufficient for protobuf, but this will be seen once the errors with rules_kotlin are fixed (maybe upgrade to rules_kotlin 2.0.0 will be enough).

Moreover, please note that migration of rules_python to Automatic Exec Groups is blocked by this migration. Hence, multiple other projects depending on rules_python are blocked (check 19981). I'd appreciate if we can move forward as soon as possible (we even planned flipping this flag in October but postponed it in order not to break significant number of users).

Please let me know if you have any questions/help.