A published library /is/ an interface specification. Fixing bugs or extending the interface (with additional and possibly corrected parameters) is one thing.

A published library /is/ an interface specification. Fixing bugs or extending the interface (with additional and possibly corrected parameters) is one thing. If the interface specification ever needs to have backward incompatible changes, the /library/ needs to be renamed (or at least have a different leading import path). If something doesn't work, development's answers is always going to be "test it with the latest version" (at least shipped, if not the 'git HEAD').