I have recently installed PostgreSQL on my Mac via Homebrew. (I may have already had it installed; it was not running.)
brew install postgres ln -sfv /usr/local/opt/postgresql/*.plist ~/Library/LaunchAgents
Now I am trying to start it with
launchctl load ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist
...but I am getting an error:
/usr/local/Cellar/postgresql/9.4.0/homebrew.mxcl.postgresql.plist: Operation not permitted
What does this error mean? What am I doing wrong? How can I fix the problem?