In the 1.5.7 runtime, the prototype for fdatasync exists in /usr/include/sys/unistd.h, but it is nowhere to be found in the actual import library.
Is this a newlib or a cygwin bug? Reproducint the bug: $ grep fdatasync /usr/include/sys/unistd.h $ nm /usr/lib/libc.a | grep 'T __fdatasync' -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/