--incompatible_no_implicit_watch_label

[fmeum]

Motivation

Historically, the path method applied to a Label on repository_ctx and module_ctx has been the only way to get Bazel to watch a file. Since the introduction of the watch method and watch parameters on many other methods, there are far more flexible and consistent ways to watch paths. Furthermore, watch = No is currently not honored when passing a Label to any of these methods, which directly contradicts the intended behavior.

Description

The repository_ctx.path and module_ctx.path methods no longer cause the argument to be watched (previously, they did if and only if the argument is a Label).

Other methods on the context objects no longer watch Label arguments with watch = No.

Incompatible Flag

--incompatible_no_implicit_watch_label

Migration Guide

If any method with a watch parameter is used on the path returned by path, no action needs to be taken since it will be watched automatically in all versions of Bazel with the incompatible flag.

In other cases, explicitly call watch on the method if available, which can be tested with hasattr on the context object.

In which Bazel LTS version will this incompatible change be enabled?

Bazel 8

Additional Context

No response

TODO List

No response