Normally the web folders on OS X are pre set with the right access rights. However when you migrate between versions, or installs, you may encounter a different situation, as I did. Which is why I got an annoying You don’t have permission to access / on this server. That is easily solved I hear you think, just by chmod-ding your Sites folder to 755 (rwxr-xr-x). Nothing more beyond the truth in my case.

After a decent amount of research on the web – and I like to think of myself as a good searcher – I found the issue is in the OS ACL entries, which you do not see (or only partly) in the GUI nor with the normal unix commands. However if you type ls -le you may see one or more extra lines underneath the folders normal listing, for example with something like 0: group:_guest deny list. The solution for this? Remove the ACL with chmod -N foldername.