Greetings, tl;dr: Need to remove npy_3kcompat.h from any source code location since Python2 is no longer supported. Background: Ran into an error after compiling various apps regarding npy_PyErr_ChainExceptionsCause() being undefined at runtime. Poking around shows that this is related to npy_3kcompat.h, which seems to be for Python2 compatibility. (There is a differently named counterpart for Python3.) This seems to be used in a couple of numpy/core/src/multiarray files. Seems that since Python2 is no longer supported, cleaning up cruft of P2 will improve code and should eliminate the problem I ran into, (or else move an error report to something else...) Is this reasonable to eliminate? Regards, ..Otto (Still getting my feet wet in numpy, scipy, etc.)