After installing Cygwin when I tried to start the shell from a Windows command prompt by entering the “sh” command a window would pop up with this error.

The procedure entry point rl_getenv_hook could not be located in the dynamic link library cygreadline6.dll.

After seeing this error I would have to manually kill the sh process using the Windows Task Manager.

There was a thread about this on the Cygwin mailing list. I did what was suggested and discovered that bin/sh.exe and bin/bash.exe were exactly the same. Yet for some reason when I ran bash from the Windows command prompt I did not get this error.

I then tried rerunning the Cygwin installer. Even though nothing was installed that seemed to solve the problem, i.e. I was able to run sh from the Windows command prompt. This was possibly because the bash postinstall script was run correctly.

Update: After reboot I am experiencing the same problem again. Aargh! 🙁