ModuleSpec.Builder uses

private final Set<DependencySpec.Builder> dependencyBuilders = new HashSet<DependencySpec.Builder>();

which causes a random order of dependencies in the Module

A client cannot make deterministic decisions on the order of dependencies.

In OSGi every bundle has a dependency on the Framework bundle which must be considered first.

Also consider the general case where multiple dependent modules export the same path.

I suggest to change this to a List also because on the ModuleSpec the dependencies are handled as array anyway.