Normally not the right way of doing things, but I have a small project where I want a provided library to live in source control with the project.
A Maven-friendly Pattern for Storing Dependencies in Version Control (for multi-module where you want the jar available without repeating yourself)
One gotcha - I initially called my 'local' repo 'local', which Maven didn't like, with a gentle warning lost in the reams of maveny grumbling.
Update: after all of that, still no joy, since provided jar had classes in default package, and you can only use classes in the default package if your own code is in the default package too. Ah well.