I'm using the following code in a BuildServerAdapter:
UserSet<SUser> users = build.getCommitters(SelectPrevBuildPolicy.SINCE_LAST_BUILD);
It seems like this set is empty when it is a build started event when there are actually committers. Is this supposed to be? The expected set of users is returned for other build events, AFAICT. What I expect, is a set of users for the currently running build. The only other option is to use SelectPrevBuildPolicy.SINCE_LAST_SUCCESSFULLY_FINISHED_BUILD.
The full code can be viewed on GitHub, as well as some more issue details.