> How can a license be incompatible with only the latter then?
Your parent comment said no such thing. It says, that you need GPL v3 to be compatible with Apache 2. "Or later" clause on GPL 2-licensed project offers you a way to re-license the project under GPL v3.
Your parent comment said no such thing. It says, that you need GPL v3 to be compatible with Apache 2. "Or later" clause on GPL 2-licensed project offers you a way to re-license the project under GPL v3.