zeromq/czmq — pull request #202 by hintjens (2013-06-28 07:45:17+00:00)
Title: Problem: errno is DLL specific on Windows (#199)

On Windows, errno is a per-DLL variable, so when libzmq is in a different
DLL than libczmq, using errno directly won't access the real value set in
libzmq code. Calling zmq_errno() fetches libzmq's instance of errno.