How to handle typechecker specific bugs

In the past, we've worked around typechecker bugs and missing features in typeshed. But as the amount of typecheckers grows and type stubs are used for more that just type checking, I don't think we can work around any bug or missing feature of every typechecker in typeshed, especially if this means regressing our stubs. Not only is this more maintainer work and it gets hard to remember which typechecker has which bug, it also means that users of bug-free typecheckers and other software will still be affected by those bugs.

I think that we should still accommodate very impactful bugs and missing major features (per our "tracking" bugs) for the "big four" mypy, pytype, pyright, and pyre. We also need to work around some bugs due to our tests. But apart from that, we should work with typecheck authors (and there is some overlap here, of course) to come up with a solution.

Regarding stdlib stubs, I believe one option is that typecheckers ship with a customized version of typeshed for major problems. Apart from that, it's always possible for users to # type: ignore a problem with a specific typechecker.

首先阅读 issue 讨论，以及针对 mypy、pytype、pyright 和 pyre 所引用的跟踪 bug。这是一个政策/设计问题，而不是一个局部实现任务；只有在维护者和类型检查器作者就应如何处理重大 bug 和缺失功能达成一致后，才算完成。