This gets encoded in wheels as platform tag and newer pip has started to verify those match the installed python. So everytime we update cygwin pip will complain about all Python packages: $ pip check ...

In Cygwin environment python crashes during loading any pkcs11 library - tested on current Cygwin release, 64-bit, windows 10 pro 64-bit. It is caused by #pragma pack in cryptoki.h - after commenting ...