Typically, as soon as I merge, I spot an edge case issue.

PySys_Audit(n, "O", a) is deliberately going to treat 'a' as the tuple of arguments (when it is a tuple). This lets us simplify/optimise events where the event arguments match the function arguments exactly. If 'a' is not a tuple, it gets wrapped in one.

When 'a' is meant to be a single argument that _might_ be a tuple, such as in PyObj_FromPtr, the format string needs to be "(O)" to ensure it is treated as a one element tuple. This is just how Py_BuildValue works - multiple elements become a tuple and the parens are optional unless you want a one-element tuple.