Although you might be distributing code that cannot function independently, you are not copying the original code, so you don't need the permission of its author.
Something we cannot examine without the sources. To make sure the code is independent we need to compare their module with our code and sample sources.
Please also note that the EU Copyright Directive for Computer Programmes also includes a statement that even allows reverse- engineering to make other software interoperable. So a licence clause that disallows (proprietary) interoperable software should be void in most member states.
Interoperability is no problem for GPL'ed software, as you always get the sources. The other way round is the problem - distributing closed source products based on GPL'ed sources.
Jan Wildeboer