You can’t start a multi-site install from scratch, you have to install the base site first, then turn on multi-site. If you turn it on right out of the box, you’ll get stuck with a database error and probably spend an hour messing with MySQL permissions before you figure it out. Don’t ask how I know 😉
Also, for running WordPress locally, it took a while to get auto-update working (it’s easier to use than than update manually on the local machine).
To do that I had to enable FTP on this machine, which I kind of hate to do because it’s a security hole. But to do that, execute this command:
sudo launchctl load -w /System/Library/LaunchDaemons/ftp.plist
When wordpress asks for FTP info, you can use ‘localhost’ as the hostname
permissions updates may have been a factor, but I’m not sure, but mostly it just worked
The big revelation is the steps for multi-site setup. The wordpress docs are weak in this area. I really wish they would create two different documents, one for subdomain, one for subfolder, because it’s a lot of work to mentally filter out one or the other as you’re reading the document, and it’s easy to miss details.
Of particular note is that first, you turn on wp_allow_multisite, then the Network settings item appears in your admin, then you enable the network, THEN you add the code it recommentds, includeing the MULTISITE=true item