# File lib/capistrano/recipes/deploy/scm/accurev.rb, line 95
        def diff(from, to=head)
          from = InternalRevision.parse(from)
          to = InternalRevision.parse(to)

          from_stream = "#{from.stream}-capistrano-diff-from"
          to_stream = "#{to.stream}-capistrano-diff-to"

          [
            change_or_create_stream(from_stream, from),
            change_or_create_stream(to_stream, to),
            scm(:diff, '-v', from_stream, '-V', to_stream, '-a')
          ].join(' && ')
        end