def use_clean_gemset(gemset)
run_simple(%{rvm gemset create "#{gemset}"}, true)
if all_stdout =~ /'#{gemset}' gemset created \((.*)\)\./
gem_home = $1
set_env('GEM_HOME', gem_home)
set_env('GEM_PATH', gem_home)
set_env('BUNDLE_PATH', gem_home)
paths = (ENV['PATH'] || "").split(File::PATH_SEPARATOR)
paths.unshift(File.join(gem_home, 'bin'))
set_env('PATH', paths.uniq.join(File::PATH_SEPARATOR))
run_simple("gem install bundler", true)
else
raise "I didn't understand rvm's output: #{all_stdout}"
end
end