Got stuck with this error on Fedora 17 while trying to get a project onto Heroku:

Error: uninitialized constant Heroku::API (NameError)

After some quick back and forth with the Heroku guys I finally got it fixed:

$  rvm uninstall 1.9.3  $  rvm reset $  sudo yum reinstall openssl openssl-devel $  rvm install 1.9.3  $  rvm use 1.9.3 —default $  heroku login

Hope this helps someone else :)