Thanks for the advice. So I tried both....
Installed guard-shell and run guard in debug.
Then still no sign of life using guard-shell. I created a simple test.txt file in the root of the directory Guard is monitoring and edited the file.
Debug doesn't output much. Terminal output:
Last login: Wed Nov 21 23:24:00 on ttys000
unknown-00-26-08-dd-0b-47:~ Rich$ cd /web/guardtest/
unknown-00-26-08-dd-0b-47:guardtest Rich$ guard --debug
23:30:02 - DEBUG - Command execution: emacsclient --eval '1' 2> /dev/null || echo 'N/A'
23:30:02 - INFO - Guard uses TerminalTitle to send notifications.
23:30:02 - INFO - Guard is now watching at '/Web/guardtest'
23:30:02 - DEBUG - Hook :start_begin executed for Guard::Compass
23:30:02 - INFO - Guard::Compass is watching at your stylesheets.
23:30:02 - DEBUG - Hook :start_end executed for Guard::Compass
23:30:02 - DEBUG - Hook :start_begin executed for Guard::Shell
23:30:02 - DEBUG - Hook :start_end executed for Guard::Shell
23:30:02 - DEBUG - Command execution: hash stty
23:30:02 - DEBUG - Command execution: stty -g 2>/dev/null
23:30:02 - DEBUG - Start interactor
[1] guard(main)>