Easily deduce and control which version of transitive Bazel dependencies gets loaded

[vmax]

It's possible for one Bazel repository to be loaded multiple times & therefore it's unclear which version gets loaded

Ex: rules_pkg is loaded by both rules_docker and vaticle_bazel_distribution. rules_docker loads v1 and vaticle_bazel_distribution loads v2 and which version gets used is controlled by their ordering in WORKSPACE file.

Goal:

• easily deduce which version gets loaded by reading WORKSPACE file
• control which version gets loaded

[alexjpwalker]

This is definitely still an issue today: we observed it recently with rules_pkg again. But it's unclear if it's the expected Bazel behaviour or not. Would be worth some research.