'rvm gem' - Working with rubygems for rubies
~/projects/ruby/extlib [git:master] $ rvm 1.8.6,1.9.1 do gem install rspec json --no-rdoc --no-ri ruby-1.8.6-p383: ruby 1.8.6 (2009-08-04 patchlevel 383) [i686-darwin10.0.0] ************************************************** Thank you for installing rspec-1.2.8 Please be sure to read History.rdoc and Upgrade.rdoc for useful information about this release. ************************************************** Successfully installed rspec-1.2.8 Building native extensions. This could take a while... Successfully installed json-1.1.9 2 gems installed ruby-1.9.1-p243: ruby 1.9.1p243 (2009-07-16 revision 24175) [i386-darwin10.0.0] ************************************************** Thank you for installing rspec-1.2.8 Please be sure to read History.rdoc and Upgrade.rdoc for useful information about this release. ************************************************** Successfully installed rspec-1.2.8 Building native extensions. This could take a while... Successfully installed json-1.1.9 2 gems installed
NOTE: If you do not pass a single or multiple rubies to act against, the command will be executed against all rubies installed on the system by RVM!
The use of the 'rvm' keyword is not used when operating against the currently active ruby and, additionally, gemset.