added a comment - - edited
I misspoke. It's actually a problem for the package phase (or for MWAR). Right now, the assumption is that all dependencies of compile scope are also necessary for packaging. That's not necessarily correct. If a library is only need for compile scope (such as annotation processor), it gets bundled into WEB-INF/lib. While not necessarily directly related to this ticket, a new possible scope would be great for this purpose. Is it simply a matter of packaging exclusion or is it really another scope?
How is test scope the inverse? If it is only needed for compiling, it doesn't need to be loaded for testing either.
By the way, I know a plus-sign can have the same semantics as a comma (i.e., logical or), but if you used the comma it could leave room for future expansion. Maybe one day users could configure any combination of scopes. Specifying "compile,runtime" seems like the natural path, imo.