The exact same thing happened to me after I did a cygwin update, vim won't start, code 127. Adding clear.exe did nothing.
strace vim +q
gave sigalstack could not be located in the dll cygwin1.dll The kind folks at the cygwin mailing list said my update probably did not complete becuase i did not close all my cygwin processes. Indeed I had sshd and cygrunsrv going, I killed those, and reinstalled cygwin base (go into setup and manually select reinstall cygwin base) this fixed everything. Good luck friends