Scala SBT: triggering an action when changing local dependencies

In SBT, you can use the “~” sign to trigger actions whenever the source file changes. For instance,

sbt> ~test

will run unit tests whenever the source changes.

Is there a good way to trigger actions when changing a source or changing a local dependency? This would be useful while developing two projects, where each of them depends on the other.

I know that you can get this behavior by manually specifying the path to the file or the base project , but it is fragile and SBT already knows where it gets its local artifacts, so I would like to avoid it.