Question

I am trying to configure JRuby using RVM on Ubuntu Linux. I have successfully installed RVM, but when trying to install Jruby, I get the following error:

dlitwak@ubuntu:~$ rvm install jruby-1.6.0
jruby-1.6.0 - #fetching 
jruby-1.6.0 - #extracted to /home/dlitwak/.rvm/src/jruby-1.6.0 (already extracted)
Building Nailgun
jruby-1.6.0 - #installing to /home/dlitwak/.rvm/rubies/jruby-1.6.0
**ERROR: Cannot switch to 1.6.2 for this interpreter.**
jruby-1.6.0 - #importing default gemsets (/home/dlitwak/.rvm/gemsets/)
Copying across included gems
Building native extensions.  This could take a while...
Successfully installed jruby-launcher-1.0.7-java
1 gem installed

Answer 1

I searched through the RVM source code, and the only occurrence of “for this interpreter” I could find was in rvm/scripts, where the following is:

case "$rvm_ruby_string" in
  jruby*|goru*|maglev*)
    install=0
    ;;
  *)
    install=1
    ;;
esac

if (( install == 0 ))
then
  rvm_error "Cannot switch to RubyGems ${version} for this interpreter."
  exit 1
fi

So it seems like that error will always show up for JRuby, which leads me to believe it’s more of a warning than an error.