Oh ok so all that happens at build is that there's an additional check against the comparator repo, the resulting repo (if the check succeeds) would be the exactly same that would be produced if I hadn't used the comparator at all?
Almost, but not exactly.
The comparison happens at artifact grain. So if you have 3 bundles/modules A1,B1,C1, you publish them in a repo, this repo is the baseline. You modify your repo:
* modify nothing => output will be the exact same A1,B1,C1 (that is not guaranteed without baseline comparison as environment like java or ecj version or build flags can lead to different output for same source)
* modify A and don't upgrade version => compare-version-with-baselines will see the binary changed for same version and fail the build when building A
* modify A and bump version to 2 => output repository will contain A2 (new) and the exact same B1, C1 as in baseline