I don't mean abandoned in a particularly negative sense, exactly because it's normal for research project to be left behind as you describe. But from the point

I don't mean abandoned in a particularly negative sense, exactly because it's normal for research project to be left behind as you describe. But from the point of view of a potential user, this kind of software is undeveloped, unsupported and rotting away (e.g. about two Clang versions behind): probably useful as a prototype to plunder and reimplement, not as a tool to get things done.