kewin@kewin:~/foreman/foreman$ rvm get latest

kewin@kewin:~/foreman/foreman$ rvm list

rvm rubies

   ruby-1.8.7-p352 [ i686 ]
   ruby-1.9.2-p290 [ i686 ]
   ruby-1.9.3-p0 [ i686 ]

# # => - current
# # =* - current && default
# #  * - default

kewin@kewin:~/foreman/foreman$ rvm use 1.8.7
#ruby ruby-1.8.7-p357 is not installed.
#To install do: 'rvm install ruby-1.8.7-p357'

请问如何处理啊？