I ran across this error when I accidentally did $ cd JDK9
instead of $ cd jdk9 No matter what I did, cd’ing in/out of directory again, blowing away build/* and starting over, etc., I could not get it to forget the upper case JDK9. And I couldn’t find that string in any file anywhere (at least any relevant file). I tried mv’ing the top level directory to jdk9-bad, but then I got other makefile errors. But then I mv’ed it back to jdk9 and voila! I could build again. Clearly magical. BTW, I’m running OS X 10.10.4
