When I tried to change to the cedar-14 stack, I got an error saying stack:set didn’t exist, so I upgraded the heroku command.

Error Message

$ heroku stack:set cedar-14 -a your-app-name
 !    `stack:set` is not a heroku command.
 !    See `heroku help` for a list of available commands.

Checking Heroku Command Version

$ heroku version
heroku-toolbelt/3.7.2 (x86_64-darwin10.8.0) ruby/1.9.3

Upgrading Heroku Command Version

$ heroku update
Installing Heroku Toolbelt v4... done.
For more information on Toolbelt v4: https://github.com/heroku/heroku-cli
Setting up node-v4.1.0...done
Installing core plugins heroku-apps, heroku-fork, heroku-git, heroku-local, heroku-run, heroku-status... done
Your version of git is 1.8.4.3. Which has serious security vulnerabilities.
More information here: https://blog.heroku.com/archives/2014/12/23/update_your_git_clients_on_windows_and_os_x
Setting up node-v4.1.0...done
Updating plugins... done

I rarely upgrade the heroku command unless errors occur with unusable commands like this.

That’s all from the Gemba.