#18050 Adjust rule registration to allow for re-exporting your imports Issue created by stuhood Currently,

@rule

registration is a flat list of

@rule

arguments, usually (mostly) generated by

collect_rules

. But it's frequently the case that additional (transitive) `@rule`s are necessary in order to actually consume a set of `@rule`s. Authors usually make this easier for consumers by splatting additional lists of `@rule`s to the flat list, and then relying on the

RuleIndex

to dedupe the redundant

@rules

. But this results in `@rule`s being exported from multiple backends (or at least multiple modules), so it's more challenging to determine the actual source of a

@rule

(for documentation, etc). pantsbuild/pants