This topic is also discussed at: https://bugs.python.org/issue43503
- specify that a subset of the limited API that extensions must target
in order to support for subinterpreters (i.e. "Py_LIMITED_PLUS_SUBINTERPRETERS_API")
Right, and let's call it "Stable ABI 4.0" :)
Since it would be a subset of the API, I understand it "just" would a subset of the ABI and so that the current stable ABI can be used. It's just that subinterpreter would not use some symbols like "PyLong_Type" (static types).
Night gathers, and now my watch begins. It shall not end until my death.