I get the error "Could not find capistrano-2.9.0 in any of the sources" with Ruby on

Hi,
I try to install Diaspora and I get this error “Could not find capistrano-2.9.0 in any of the sources” and I can not solve it.
Can you help me to resolve the problem.
Thanks

Have you tried this?


# gem install capistrano

Yes, I already tried.

Have you tried using bundle install?