GTAGS not found error

Question

I'm trying to use gtags to provide extra info to my semantic installation.

I successfully generate the GTAGS file (and other support files).

When I try the command 'gtags -pvr', I get this output, which seems right:

checking Y://GTAGS
GTAGS found at 'Y://GTAGS'
Y:/

Now if I run global to try and find a tag that I know exists:

global -v foo

I just get the error message

global: GTAGS not found.

I've tried a bunch of different combinations of setting the GTAGSDBPATH and GTAGSROOT variables, with no joy.

I've tried it both in cygwin/bash and the windows cmd terminal. Emacs (23.2.1) predictably complains that it can't find GTAGS either. This is windows Vista, and the latest Global windows build linked from the main site.