A weird edge case came up today around a buildpack that turned out to be unneeded for my application. How do you change the Buildpack once you’ve associated it with your application? It turns out that a Buildpack is essentially just a piece of config, so you can see it and change it by using the heroku config command and the config variable name BUILDPACK_URL.
In my case I just needed to remove the configured Buildpack with a simple heroku config unset command:
heroku config:unset BUILDPACK_URL
Echo One 
FYI: Command should be `heroku config:unset BUILDPACK_URL` (note colon)
Thank you. I’ve updated the post to have something cut and pastable!
Looks great!
`heroku buildpack:remove BUILDPACK_URL` should do the trick now.
for me heroku required ‘buildpack’ to be plural, e.g. ‘heroku build packs:remove heroku/php’