b43adff637
Certain dependency strings could have cross-SLOT scope (multiple slots for same package are valid) causing unwanted dependencies to be pulled in. For example: if dependency is "dev-lang/python" and we have dev-lang/python-2 installed, python-3 should be filtered out (if possible) by checking if the installed best dependency match slot is still available in repositories. If it is, restrict the dependency scope to the intersection between available SLOTs and installed SLOT.