Given what you have here, if you have no output than you successfully iterated the ../projects directory with the glob and returned matching subdirectories. The only time you'll have output is on an error.
If there's more to it than this, than I'd suggest checking the HTML output to see if its a white page, or if it has PHP embedded within it. If it has PHP embedded, you simply don't have the server set up to process PHP code.
header('HTTP/1.1 420 Enhance Your Calm');