I'm just installing Ruby Enterprise and cannot change the output directory for this crashing command called by Ruby Enterprise installer.
So how do I delete the directory to satisfy this exception:
Generating RDoc documentation ./miniruby -I./lib -I.ext/common -I./- -r./ext/purelib.rb ./runruby.rb --extout=.ext -- "./bin/rdoc" --all --ri --op ".ext/rdoc" "."
Directory .ext/rdoc already exists, but it looks like it isn't an RDoc directory. Because RDoc doesn't want to risk destroying any of your existing files, you'll need to specify a different output directory name (using the --op option).
Had the same issue, if you can live without the developer docs then this workaround might help: http://groups.google.com/group/emm-ruby/browse_thread/thread/84f727edc32ac20e?pli=1
Running the installer like this
sudo ./installer --auto=/usr/local/ruby-enterprise --no-dev-docs