Hello all, I wanted to try to get some traction on this issue that I raised on the Cython-user google group list: https://groups.google.com/forum/#!topic/cython-users/l9wD4w2lcw8 The basic issue is that I get an error of "undefined reference to `__Pyx_PyInt_As_unsigned_int". The strange part is I then get non-deterministic codegen, wherein the first time I compile the code it fails, but if I delete the .c file and try again, it will then compile without errors. A minimal example is provided here: https://gist.github.com/synapticarbors/11060931 This issue seems to have cropped up somewhere between 0.19.2 (where it's fine) and 0.20.1. It also is still present in 0.21dev from github. The error seems to happen when running on a Windows machine (Windows 2008 server), but I can't reproduce the error on Mac OSX (running the same version of the Continuum Anaconda distribution). Any suggestions or confirmation of this issue would be appreciated. Thanks, Josh