nzoschke

as a buildpack maintainer

$ git clone https://github.com/heroku/heroku-buildpack-ruby.git  # or any other buildpack
$ cd heroku-buildpack-ruby
heroku-buildpack-ruby $ cat Dockerfile
FROM fabiokung/heroku-buildpack-base

RUN DEBIAN_FRONTEND=noninteractive apt-get install -y -q ruby2.0
# more stuff specific to this buildpack...