When you delete a gemset, rvm will prompt you to confirm the deletion.
$ rvm gemset use albinochipmunk $ rvm gemset delete albinochipmunk
To skip confirmation, pass the --force flag:
$ rvm gemset use albinochipmunk $ rvm --force gemset delete albinochipmunk
By default, rvm deletes gemsets from the currently selected Ruby interpreter. To delete a gemset from a different interpreter, say 1.9.2, run your command this way:
$ rvm 1.9.2 do gemset delete albinochipmunk
