Having a bit of an issue with PostgreSQL on Mac OS X 10.8.4. I accidentally did brew rm postgresql --force while the postgres server was running. When I install
brew rm postgresql --force
I was having the same problem...removing the launch agent solved the problem for me:
launchctl unload -w ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist rm ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist