There are common libraries which do things incompatible with the way pypy works. I've never gotten it to do anything but abort, when run over a non-trivial program.

mypy is a very cool experimental project (as their own webpage calls it), but I wouldn't fault anyone for not running it on their program.

The question, then, is why that kind of analysis isn't built into the compiler?

> Despite considerable discussion about a standard type parameterisation syntax, it was decided that this should also be left to third-party libraries. ([7], [8], [9]).

> Despite yet more discussion, it was decided not to standardize a mechanism for annotation interoperability. Standardizing interoperability conventions at this point would be premature. We would rather let these conventions develop organically, based on real-world usage and necessity, than try to force all users into some contrived scheme. ([14], [15], [16]).

That doesn't sound really "batteries included" to me.

Is there a single programming language for which static analyzers are a part of the language rather than external tools?