I recently undid all my MacPorts and started using Homebrew for some software on my Macs. That meant uninstalling the Apache MacPort and switching back to the default Snow Leopard version of Apache. Everything went relatively smoothly but today a noticed that my Passenger prefpane wasn’t listing all the Rails sites it had previously been managing.
Turns out it was because in my original install of the prefpane I had used the “ports” version of a required ruby file, per instructions, since I was using the MacPort version of Apache. The easy fix is to just reinstall the prefpane. All of my sites now show up in the site listing and I can add the new site I’m currently developing.