Dear Numpy developers, I'm trying to write a version of the variance function that does not use temporary array. I got something that start to be functional (the branch is located here https://github.com/mbarbry/numpy/tree/sum_square_shift) but when running the tests I get the following memory error, Running unit tests for numpy NumPy version 1.14.0.dev0+f9db20b NumPy relaxed strides checking option: True NumPy is installed in /home/marc/programs/python/my_numpy/local/lib/python2.7/site-packages/numpy-1.14.0.dev0+f9db20b-py2.7-linux-x86_64.egg/numpy Python version 2.7.12 (default, Nov 19 2016, 06:48:10) [GCC 5.4.0 20160609] nose version 1.3.7 Program received signal SIGSEGV, Segmentation fault. 0x00007ffff1ef1f6d in inittest_rational () at numpy/core/src/umath/test_rational.c.src:1262 1262 REGISTER_UFUNC_BINARY_RATIONAL(add) This is weird because I didn't touch the umath module, I'm working in the multiarray one. Do you have a idea how I can debug this? Thanks for your help, Marc Barbry