I run many firefox profiles simultaneously. Since moving to the mac, I've lost the British English dictionary. I can install it as an extension on each profile, but I'd like to install it once across all profiles.
firefox -install-global-extension "/path/to/extension.xpi" but that appears to have no effect whatsoever. I've tried copying the installed extension into various folders in
~/Library but nothing has worked.
How do I install a Firefox extension once so it is active for all profiles on the computer (or this user account, either is good)?