I was having troubles with autotest, and not really finding a good solution. But i noticed that inside rspec2 they were using watchr.

Watchr is a very generic gem that will allow you to watch a set of files and take action when something changes. That sounds great, but maybe a bit too general :)

So, it appears you need a script to run your rspec2 continuously using watchr. Luckily i did find some examples, which allowed my to brew my own (save in your rails-root as specs.watchr):

# adapted from http://github.com/rspec/rspec-rails/blob/master/specs.watchr

# Run me with:
#
#   $ watchr specs.watchr

# --------------------------------------------------
# Convenience Methods
# --------------------------------------------------
def all_spec_files
  Dir['spec/**/*_spec.rb']
end

def run_spec_matching(thing_to_match)
  matches = all_spec_files.grep(/#{thing_to_match}/i)
  if matches.empty?
    puts "Sorry, thanks for playing, but there were no matches for #{thing_to_match}"
  else
    run matches.join(' ')
  end
end

def run(files_to_run)
  puts("Running: #{files_to_run}")
  system("rspec -c #{files_to_run}")
  no_int_for_you
end

def run_all_specs
  run(all_spec_files.join(' '))
end

# --------------------------------------------------
# Watchr Rules
# --------------------------------------------------
watch('^spec/(.*)_spec\.rb')    { |m| run_spec_matching(m[1]) }
watch('^app/(.*)\.rb')          { |m| run_spec_matching(m[1]) }
watch('^app/(.*)\.haml')        { |m| run_spec_matching(m[1]) }
watch('^lib/(.*)\.rb')          { |m| run_spec_matching(m[1]) }
watch('^spec/spec_helper\.rb')  { run_all_specs }
watch('^spec/support/.*\.rb')   { run_all_specs }

# --------------------------------------------------
# Signal Handling
# --------------------------------------------------

def no_int_for_you
  @sent_an_int = nil
end

Signal.trap 'INT' do
  if @sent_an_int then
    puts "   A second INT?  Ok, I get the message.  Shutting down now."
    exit
  else
    puts "   Did you just send me an INT? Ugh.  I'll quit for real if you do it again."
    @sent_an_int = true
    Kernel.sleep 1.5
    run_all_specs
  end
end

It even seems to be quicker than autotest, but not sure if that is just wishful thinking.