It would be useful to have an option to only operate on a change that has no dependencies.

Developers sometimes push sets of patches that in terms of git commits are independent of each other but in terms of building/testing, should be treated as an atomic set. That is, a developer might push 5 commits for review all at once. Gerrit actually tracks the fact that these 5 patches have a dependency relationship amongst them (i.e. 2 depends on 1, 3 depends on 2, etc.). Typically in such a case, the developer only cares if the whole set builds and passes tests or not and is not interested in each of the 5 patches individually.

To that end, it would be nice if the Gerrit trigger could be told to treat these sets as one logical job and to only do one build/test for them all.

Doing a build/test for each patch individually is fine when such builds and tests are cheap to run, but when you have a test that takes many hours, having to run that test * number of patches is wasteful on time and resources, when all that anyone cares about is the last one that encompasses all of the changes.