I tried building node.js on cygwin and that caused errors, so someone in #node.js on freenode told me to run rebaseall on cygwin to clean it up. So I tried that and I got the following message:

$ rebaseall

rebaseall: only ash or dash processes are allowed during rebasing

Exit all Cygwin processes and stop all Cygwin services.

Execute ash (or dash) from Start/Run... or a cmd or command window.

Execute '/bin/rebaseall' from ash (or dash).

So I closed cygwin, went to Start/Run and tried ash and dash but got the following alert:

Windows cannot find 'ash'. Make sure you typed the name correctly, and then try again. To search for a file, click the Start button, and then click Search.

So what am I supposed to do??