I've been following the reInteractive ruby on rails (15 min blog), and in the end of the post (second part), I got an error using heroku to upload my files:
! Precompiling assests failed
!Push rejected, failed to compile Ruby app
To git@heroku.com:peaceful-sea-8032.git
! [remote rejected] master -> master <pre-receive hook declined>
error: failed to push some refs to 'git@heroku.com:peaceful-sea-8032.git'
ps: The app runs fine on localhost, I saw some similar question but I did not have success trying their solutions.