No need to do an incref, sincePyTuple_New returns a new reference that gets implicitly transferred to__mypyc_empty_tuple__.

Also use the new primitive innew_tuple_with_length below if length == 0.

I'm not sure how to implement this logic at compile time because in this location,length is a Value not a known integer

we could do a boolean op to check, but then we're just recreating what already exists in PyTuple_New and making our IR longer to do it

You are correct, please disregard my above comment.

The new function could be used inmypyc/codegen/emit.py on this line when generating C for a box operation:self.emit_line(f"{declaration}{dest} = PyTuple_New({len(typ.types)});"). If length is zero, we could use the new primitive?

looks correct. We can also skip the subsequent NULL check. I've implemented this and the tests are running, I may need to update the IR test definitons.