reloving dependencies from unneeded projects in depended builds

I have a Build containing a Project that depends on another Project using ProjectRef from a different Build on Github that contains multiple Projects. The specific Project that I depend on is OK and has no unresolved dependencies so I can run the update and compile tasks without dependency errors. However, when I run the eclipse task, sbt is attempting to resolve dependencies from other projects I do not depend on in the same Build as the project I do depend on that happen to be broken, which leads to unresolved dependency errors and makes the eclipse task stop without producing the project files.

e.g.

 Build1 {
  val myProject = Project(...).dependsOn(ProjectRef(uri(...Build2Repo...), "dependedProject"))
}

then in the repo on github (not mine)

Build2 {
  val dependedProject = Project(...)
  val fooProject = Project(...).dependsOn(dependedProject)
  val barProject = Project(...).dependsOn(fooProject)
}

when I run eclipse task (but not update task) sbt is trying to resolve dependencies in fooProject and BarProject even though dependedProject does not depend on them and neither does my project.

Start by reproducing the described Build1/Build2 setup and compare the eclipse task with update and compile. Trace why eclipse resolves dependencies from unrelated projects such as fooProject and barProject; done when eclipse generates the project files while resolving only the dependedProject dependency graph.