Hi all, I just released Cython 0.29.4 with an important bug fix(*) for division operations that involve constant numerators. If the denominator turns out to be zero at runtime, it could happen that no ZeroDivisionError gets raised, and instead an arbitrary result returned. https://github.com/cython/cython/issues/2820 Upgrading is recommended to restore correctness. Stefan (*) You could argue that support for division by zero is a rather oustanding feature, but … I think the surprise factor outweighs the coolness here.