Reinstalling MySQL on OSX using Homebrew

Thu Jan 28, 2016
~300 Words

If you find that you need to have a particular version of MySQL installed on your OSX machine (e.g. to match the version running in production) but you already have a different version of MySQL installed via Homebrew, then the notes below may help you to replace the installed version with the one you need.

DISCLAIMER: The following instructions involve the complete removal of the existing MySQL installation, including any databases. Proceed with caution, and double check every command–this is just meant to be a rough guide to an approach you can take to achieve the desired result.

Uninstalling

  1. Check ~/Library/LaunchAgents, if homebrew.mxcl.mysql.plist is present then:
    1. Unload: launchctl unload -w ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist
    2. Remove: rm ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist
  2. Stop the MySQL server process: sudo mysql.server stop
  3. brew remove mysql
  4. brew cleanup (note that this command will clean up after more than just MySQL)
  5. Remove if present:
    1. /usr/local/var/mysql

Reinstalling

  1. Select the version that you want to install (in my case, 5.5.x)
  2. brew tap homebrew/versions
  3. brew install mysql55
  4. Follow the post-install instructions as provided by the brew install output
  5. Add the appropriate directoy to your PATH, e.g. /usr/local/opt/mysql55/bin

Post-install instructions

Yours may differ from the below.

To have launchd start homebrew/versions/mysql55 at login:
  ln -sfv /usr/local/opt/mysql55/*.plist ~/Library/LaunchAgents
Then to load homebrew/versions/mysql55 now:
  launchctl load ~/Library/LaunchAgents/homebrew.mxcl.mysql55.plist
Or, if you don't want/need launchctl, you can just run:
  /usr/local/opt/mysql55/bin/mysql.server start

WARNING: launchctl will fail when run under tmux.

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