The multistart goal of the Swarm Maven plugin (the MultiStartMojo class) can either run the start goal on a Maven submodule (the startProject method), if the multi-started artifacts are submodules of the given module, or start a Swarm uberjar of a dependency (the startArtifact method).
So if I want to multi-start a couple of dependencies that are not my submodules, the 1st approach fails and the 2nd one is used. However, it expects that the swarm classifier is configured manually:
And that, in turn, requires the dependency on that artifact, to also specify the classifier:
Is that intentional? If yes, this should be documented and/or there should be a clear error message. Right now, if I don't configure the classifier, I only get
And it takes some time to realize that this isn't really a Swarm uberjar, and then I need to dig into the MultiStartMojo source code to realize that I can configure the classifier.