Decided to place this here instead on github as this may be fixable however I don't know.
While attempting to make my own library for making a callable-like object
That could run a little faster than pluggy and I'm making an asynchronous library for writing plugin with event-styled wrappers which is a little bit different from pluggy, this library was meant to be it's building block but I also seperated it incase users wanted to try using it for different purposes.
Onto the Meat of the problem: I bumped into a bug where when the module cleans up under random circumstances it segfaults. I originally got rid of @cython.freelist but originally I left it at 250 assuming users would make around that many of these at any given time. I got rid of this when I saw that it was segfaulting thinking that it would cure the problem but it did not.