Local versions do help a lot in private package settings when combined with constraints, but fall short when versions cannot be pinned exactly. Say I have foo-1.0+1 and foo-1.1+1 locally, there’s not a good way to specify only these versions are valid, that can guard against a potential public foo-1.1 release on PyPI. Maybe it would help if we introduce OR conditions in specifiers, but that might as well also still only solve the use case partially, while opening a gate to new problems.