>
2. Pickle support in typing is not perfect. I was going to fix it (I had almost ready code), but lost a chance of doing this before. It can be changed in 3.7.1, but this means that pickles of some derived typing types created in 3.7.0 will be not compatible with future versions (may be 3.7.1 will not break compatibility, but it will be broken in future because we will not specially supported compatibility with 3.7.0).
I think I had fixed this one. At least the examples reported on typing tracker are now fixed.
Do you have some other examples that still fail?
--
Ivan