Earlier quoted context omitted.
> problems if you link code built with different versions But that has nothing to do with semver. Semver gives you information about when when you can replace one version with another version. It doesn't promise that you can mix multiple versions together.
It gives you information about intent , not reality. And you are mixing multiple versions if you are building against version x.y and linking against version x.(y+z).
Every versioning scheme necessarily describes intent, not reality.