class RailsEnvironment

def externals
  return [] unless use_externals?
  ext = `svn propget svn:externals "#{root}/vendor/plugins"`
  lines = ext.respond_to?(:lines) ? ext.lines : ext
  lines.reject{ |line| line.strip == '' }.map do |line|
    line.strip.split(/\s+/, 2)
  end
end