Reading from stdin is very slow when a process runs outside of Cygwin Terminal.
Steps to reproduce: 1. Create "test.txt" file using python code: long_text = "10" * 2500 with open(r'test.txt', 'w') as f: for i in range(5000): f.write('KEY%03d: %d => %s\n' % (i % 100, i, long_text)) 2. Install "cygwin" package version > "3.3.6-1" 3. Open windows command prompt (cmd.exe) 4. Enter command: type test.txt | c:\cygwin64\bin\wc.exe -l When running the same command (use cat instead of type) on the Cygwin Terminal, no performance issues observed. The last version of cygwin package without issues: 3.3.6-1 Versions of cygwin package with issues: 3.4.x - 3.5.x P.S. I tested this combinations of pipings: cygwin_prog | win_prog # no issues win_prog | cygwin_prog # has issues when running in windows command prompt, no issues in Cygwin Terminal cygwin_prog | cygwin_prog # has issues when running in windows command prompt, no issues in Cygwin Terminal -- Problem reports: https://cygwin.com/problems.html FAQ: https://cygwin.com/faq/ Documentation: https://cygwin.com/docs.html Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple