This is useful for cases where the project is made available through other means when e.g. deployed. Mark said:
"Yeah, I needed something like this as well and I think the answer in theory is to declare the dependencies as "provided". Unfortunately, this isn't implemented for inter-project dependencies, but if you open a bug, I'll try to get it implemented for the next version."
See the following for the full thread:
inter-project provided dependencies, closes #53