This is the not yet the official Heroku buildpack for zbar apps. If you fork this repository, please update this README to explain what your fork does and why it's special. Seems to be working though. It compiles each time which is not ideal, but other than that it works and will allow you to use zbarimg in your apps.
Best when used with https://github.com/elbongurk/heroku-buildpack-ghostscript.git