tests/test.c fails on CygWin
This is due to sprintf("%05s","abc") results in '00abc' on CygWin / Windows but it is expected to result in ' abc' as on glibc/Linux. We could simply skip this test when we know that sprintf prepends zeroes. In the long term, we should make printf-style function to use the internal printf functions - it is faster than glibc but lacks floating point support for now.