/var/www/gitorious# env RAILS_ENV=production ruby1.8 script/create_admin 
/usr/local/rvm/gems/ruby-1.8.7-p371/gems/rails-2.3.18/lib/rails/gem_dependency.rb:21:in `add_frozen_gem_path': undefined method `source_index' for Gem:Module (NoMethodError)
	from /usr/local/rvm/gems/ruby-1.8.7-p371/gems/rails-2.3.18/lib/initializer.rb:298:in `add_gem_load_paths'
	from /usr/local/rvm/gems/ruby-1.8.7-p371/gems/rails-2.3.18/lib/initializer.rb:132:in `process'
	from /usr/local/rvm/gems/ruby-1.8.7-p371/gems/rails-2.3.18/lib/initializer.rb:113:in `send'
	from /usr/local/rvm/gems/ruby-1.8.7-p371/gems/rails-2.3.18/lib/initializer.rb:113:in `run'
	from ./script/../config/environment.rb:23
	from script/create_admin:2:in `require'
	from script/create_admin:2
/var/www/gitorious# ruby
ruby                               ruby-1.8.7-p371@global             rubygems-bundler-uninstaller
ruby1.8                            ruby-1.8.7-p371@myrails            rubygems_detect_ruby_lib_gem_path
ruby-1.8.7-p371                    rubyforge                          ruby_noexec_wrapper
/var/www/gitorious# env RAILS_ENV=production ruby1.8.7-p371 script/create_admin 
env: ruby1.8.7-p371: Datei oder Verzeichnis nicht gefunden
/var/www/gitorious# env RAILS_ENV=production ruby-1.8.7-p371 script/create_admin 
NOTE: Gem.source_index is deprecated, use Specification. It will be removed on or after 2011-11-01.
Gem.source_index called from /usr/local/rvm/gems/ruby-1.8.7-p371/gems/rails-2.3.18/lib/rails/gem_dependency.rb:21.
Type in Administrator's e-mail: 
Type in Administrator's password: 
Admin user created successfully.

loading the pape shows:
Error message:
undefined method `source_index' for Gem:Module
Exception class:
NoMethodError
Application root:
/var/www/gitorious