I have a script which does not find /dev/stderr when its stderr is redirected and piped. The minimal reproduction follows below. This is a verbatim copy from the terminal with edited-in comments prefixed with hashes.
$ uname -a CYGWIN_NT-6.1-WOW xxxxxxxx 2.8.1(0.312/5/3) 2017-07-03 14:06 i686 Cygwin $ bash --version GNU bash, version 4.4.12(3)-release (i686-pc-cygwin) [...] ######################################################## $ cat say-something.sh #!/bin/sh echo something > /dev/stderr ######################################################## ############### This is the error: $ (x=$(./say-something.sh 2> /dev/stderr)) |& cat ./say-something.sh: line 2: /dev/stderr: No such file or directory ############### Variants without sub-shell, piping or redirection work: $ (x=$(./say-something.sh 2> /dev/stderr)) | cat something $ (x=$(./say-something.sh 2> /dev/stderr)) something $ x=$(./say-something.sh 2> /dev/stderr) |& cat something $ (x=$(./say-something.sh > /dev/stderr)) |& cat something $ (x=$(./say-something.sh 2> /dev/stdout)) |& cat $ -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
