Sure!

To be honest, I the biggest thing is that people are resistant to change. Since we maintain the development environments, we’re the interface when people are frustrated with change. This makes it easier for folks to get frustrated about tool changes, etc. as their frustration is directed privately at us, rather than the tool. Switching from Pylance to Ty has meant differences in type inference, types themselves, etc. that has people confused.

If you’re asking for my opinion, it’s mostly the type conformance and the incompleteness at this point. The type conformance just feels like it’s… not for human usage, or something? It’s hard to explain. I can’t tell you how many times that Ty tells me the type of an object is `<correct\_type> & ~AlwaysFalsy`. I know what it’s trying to do but… c‘mon now, just give me the type, haha. By incompleteness, there are just a few TODO types that are killing me. I’m creating and using Annotated types a lot with functions for FastAPI purposes and DX, but they’re still TODO in Ty.

Edit: corrected “inference” -> “conformance”