[xxxxx@oc3651178580 ~]$ heroku --version
/usr/local/heroku/lib/heroku/updater.rb:3:in `require': /usr/local/heroku/lib/heroku/helpers.rb:303: syntax error, unexpected ':', expecting ')' (SyntaxError)
...de('utf-8', 'binary', invalid: :replace, undef: :replace).sp...
                          ^
from /usr/local/heroku/lib/heroku/updater.rb:3
from /usr/local/heroku/bin/heroku:18:in `require'
from /usr/local/heroku/bin/heroku:18

$ which ruby
/usr/bin/ruby

$ readlink -f /usr/bin/ruby
/usr/bin/ruby1.8

$ dpkg -S /usr/bin/ruby1.8
ruby1.8: /usr/bin/ruby1.8

$ apt-get purge ruby1.8

$ apt-get install ruby