Numpy. Here's a patch the author himself wrote to fix a spot where this change break's numpy's thread safety: https://github.com/colesbury/numpy/commit/2ad41a1

Numpy. Here's a patch the author himself wrote to fix a spot where this change break's numpy's thread safety: https://github.com/colesbury/numpy/commit/2ad41a1fb8b0c28fa86e2fd825b2194e05336649 https://github.com/colesbury/numpy/commit/2ad41a1fb8b0c28fa8... Maybe that's the only one? Maybe it isn't? But I think the point still stands that people saying this has the potential to break existing Python packages in subtle ways are not just being hyperbolic.