This is part of migrations of Automatic Exec Groups (AEGs) where a toolchain parameter should be set inside actions which use executable or tools from a toolchain.

AEGs are under an incompatible flag right now, but will be flipped soon in Bazel 7. I've added this change since I was manually fixing rules_nodejs, which depends on bazel-lib. I can't fully test this change since I need at least Bazel 7, but Bazel@Head raises non related errors to my change. That's why there might be more related updates once bazel-lib supports Bazel 7.

Still, as I already mentioned, adding a toolchain parameter is masked by the incompatible flag, so these changes don't do anything right now. But it can help you with your migration in the near future when AEGs are enabled by default and you are forced to update actions which use toolchains.

Also note that the toolchain parameter is available from Bazel 6, but the full logic (and the incompatible flag) will be available from Bazel 7.

Please check official documentation for Automatic Exec Groups for additional info.

Type of change

• New feature or functionality (change which adds functionality)

Test plan

• Manual testing; please provide instructions so we can reproduce:
• Use (at least) Bazel 7 and add --incompatible_auto_exec_groups flag.