The problem is not the .so, which has all versions, but the .o files, that don't have a way to represent the version they would prefer to use. C declarations al

The problem is not the .so, which has all versions, but the .o files, that don't have a way to represent the version they would prefer to use. C declarations also lack a way to specify those versions, and the last version is the only one that is guaranteed to correspond to what's declared in the headers (because the older versions could have a different ABI... in fact, if they did have the same ABI, a change in version wouldn't have been necessary in the first place).