guard-minitest error

minitest.txt

> bundle exec guard
Guard uses Libnotify to send notifications.
Guard is now watching at '/data/music/RotC/eventbook'
> 
Running all tests
Run options: --seed 63689
/home/adam/.rvm/gems/ruby-1.9.3-p0@rails-3.1/gems/activesupport-3.1.3/lib/active_support/whiny_nil.rb:48:in `method_missing': undefined method `/' for nil:NilClass (NoMethodError)
        from /home/adam/.rvm/gems/ruby-1.9.3-p0@rails-3.1/bundler/gems/guard-minitest-ad4cb29c78ec/lib/guard/minitest/notifier.rb:12:in `guard_message'
        from /home/adam/.rvm/gems/ruby-1.9.3-p0@rails-3.1/bundler/gems/guard-minitest-ad4cb29c78ec/lib/guard/minitest/notifier.rb:28:in `notify'
        from /home/adam/.rvm/gems/ruby-1.9.3-p0@rails-3.1/bundler/gems/guard-minitest-ad4cb29c78ec/lib/guard/minitest/runners/version_2_runner.rb:14:in `_run_anything'
        from /home/adam/.rvm/gems/ruby-1.9.3-p0@rails-3.1/gems/minitest-2.10.0/lib/minitest/unit.rb:947:in `run_tests'
        from /home/adam/.rvm/gems/ruby-1.9.3-p0@rails-3.1/gems/minitest-2.10.0/lib/minitest/unit.rb:934:in `block in _run'
        from /home/adam/.rvm/gems/ruby-1.9.3-p0@rails-3.1/gems/minitest-2.10.0/lib/minitest/unit.rb:933:in `each'
        from /home/adam/.rvm/gems/ruby-1.9.3-p0@rails-3.1/gems/minitest-2.10.0/lib/minitest/unit.rb:933:in `_run'
        from /home/adam/.rvm/gems/ruby-1.9.3-p0@rails-3.1/gems/minitest-2.10.0/lib/minitest/unit.rb:922:in `run'
        from /home/adam/.rvm/gems/ruby-1.9.3-p0@rails-3.1/gems/minitest-2.10.0/lib/minitest/unit.rb:690:in `block in autorun'
>