reinstall every gem for each ruby version?

Question

I just installed Ruby 2.0.0 using rbenv and set it to the global ruby version for my system. Since 2.0 is compatible with 1.9.3, I tried to start up a Rails project with it, but

Answer 1

As seen here:

You need to reinstall bundler for each version of Ruby you use. See Ruby versions where you have it installed:

rbenv whence bundle

See your current version:

rbenv version

Install bundler for that version, if missing:

gem install bundler