I am trying to run phantomjs on the heroku cedar stack. I am using a phantomjs buildpack for heroku https://github.com/stomita/heroku-buildpack-phantomjs. However I followed the instructions but still cannot make it work. When I run the command heroku run bash and type phantomjs --version it says phantomjs: command not found I read things about LD_LIBRARY_PATH that needs to be set to "/usr/local/lib:/usr/lib:/lib:/app/vendor/phantomjs/lib", this is what i did but without success. Is there something that i am missing ? Where does the buildpack install the phantomjs binary exactly ? Is there a way to know the path where the binary is ? I am using ruby 1.9.2 Thanks a lot for your help. EDIT: To be more precise, i want to combine ruby and phantomjs, so i am using this custom buildpack: https://github.com/ddollar/heroku-buildpack-multi, but when i push to heroku i get "Heroku push rejected, failed to compile Multipack app"