Ability to tune unused dependency handling per target

[larshagencognite]

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[Bencodes]

We'd like to avoid collecting excessive attributes like these on the top level rule definitions so that we aren't cluttering our rule definitions over time.

Would you be open to using tags to opt targets out of this feature? There are a few examples around the codebase already where we follow this pattern.

[larshagencognite]

I think tags for the unused deps report mode would work well, I assume you mean like this?

kt_experimental_report_unused_deps_off <-> experimental_report_unused_deps="off"
kt_experimental_report_unused_deps_warn <-> experimental_report_unused_deps="warn"
kt_experimental_report_unused_deps_error <-> experimental_report_unused_deps="error"

When it comes to defining a list of labels to ignore, I would assume it would have to be something like this?

kt_experimental_unused_deps_ignored_target:<target_label1>
kt_experimental_unused_deps_ignored_target:<target_label2>
kt_experimental_unused_deps_ignored_target:<target_label3>
...

Seems doable, did I capture your intention?

[restingbull]

You can leave out the kt_experimental_ for the tags. Since unused deps is going to be a fun exercise to get right, I expect this api will be around for a while.