Heroku compass buildpack compass fail

Question

I am trying to push a compass build-pack to heroku server, https://github.com/stephanmelzer/heroku-buildpack-nodejs-grunt-compass

It use to work until recently and I am not sure what happened on heroku side, it doens't work anymore and giving me this error :

bash: /app/.gem/ruby/1.9.1/bin/compass: /app/vendor/ruby-1.9.2/bin/ruby: bad interpreter: No such file or directory

I am not sure what happened did they change the ruby version or something

Does someone knows what can be the issue and the fix.

I use Cedar stack, running node

Answer 1

I'd like to add to the accepted answer with a bit more explanation since I had this exact same issue and I believe most folks will need to unset an old buildpack as follows:

First unset your old buildpack and point to the buildpack-multi:

heroku config:unset BUILDPACK_URL
heroku config:add BUILDPACK_URL=https://github.com/ddollar/heroku-buildpack-multi.git

Buildpack multi requires you to add your own .buildpacks file. This configuration is what I ended up using successfully:

cat .buildpacks
https://github.com/heroku/heroku-buildpack-nodejs.git
https://github.com/heroku/heroku-buildpack-ruby.git

Here's my Gemfile to pickup only Compass:

cat Gemfile
source 'https://rubygems.org'
gem 'compass'

Now you need to do:

bundle install

Which will add a Gemfile.lock

Commit everything to git and push back to heroku. This will kick in your new multi buildpack configuration and hopefully get you back up and running. You should see both the nodejs and ruby buildpacks download serially per above configuration.

Disclaimer: This is likely time-sensitive material as heroku might very well change something over the upcoming months.