Re: Installing to local Mac
Kinda shooting in the dark here, but will it install as http://localhost/forum/bb-admin/install.php ?
I am not sure if bbPress has to be installed with a fully qualified domain name or not.
Maybe check out this thread as well in your search.
https://mu.wordpress.org/forums/topic.php?id=1426&replies=13
(I know it is MU WordPress, but same principle may apply)
Trent