NoMethodError when using DocumentationFormatter and capybara_webkit

[andrewculver]

All of the tests passing with the default progress formatter, but things break when I try to use the documentation formatter.

The configuration file looks like this:

Konacha.configure do |config|
  require 'rspec'
  require 'rspec/core/formatters/documentation_formatter'
  require 'capybara/webkit'
  config.spec_dir     = 'spec/javascripts'
  config.spec_matcher = /_spec\.|_test\./
  config.stylesheets  = %w(application)
  config.driver       = :webkit
  config.formatters = [RSpec::Core::Formatters::DocumentationFormatter.new(STDOUT)]
end if defined?(Konacha)

When I run on the console with bundle exec rake konacha:run I get the following error and trace:

rake aborted!
NoMethodError: Error communicating with browser process: undefined method `count' for 22:Fixnum
/Users/andrewculver/.rvm/gems/ruby-2.3.0/gems/whenever-0.9.7/lib/whenever/numeric.rb:10:in `method_missing'
/Users/andrewculver/.rvm/gems/ruby-2.3.0/gems/rspec-core-3.5.4/lib/rspec/core/formatters/base_formatter.rb:34:in `start'
/Users/andrewculver/.rvm/gems/ruby-2.3.0/gems/konacha-4.0.0/lib/konacha/reporter.rb:64:in `block in process_event'
/Users/andrewculver/.rvm/gems/ruby-2.3.0/gems/konacha-4.0.0/lib/konacha/reporter.rb:63:in `each'
/Users/andrewculver/.rvm/gems/ruby-2.3.0/gems/konacha-4.0.0/lib/konacha/reporter.rb:63:in `process_event'
/Users/andrewculver/.rvm/gems/ruby-2.3.0/gems/konacha-4.0.0/lib/konacha/reporter.rb:20:in `start'
/Users/andrewculver/.rvm/gems/ruby-2.3.0/gems/konacha-4.0.0/lib/konacha/reporter.rb:88:in `handle_mocha_start'
/Users/andrewculver/.rvm/gems/ruby-2.3.0/gems/konacha-4.0.0/lib/konacha/reporter.rb:47:in `process_mocha_event'
/Users/andrewculver/.rvm/gems/ruby-2.3.0/gems/konacha-4.0.0/lib/konacha/runner.rb:28:in `block in run'
/Users/andrewculver/.rvm/gems/ruby-2.3.0/gems/konacha-4.0.0/lib/konacha/runner.rb:26:in `each'
/Users/andrewculver/.rvm/gems/ruby-2.3.0/gems/konacha-4.0.0/lib/konacha/runner.rb:26:in `run'
/Users/andrewculver/.rvm/gems/ruby-2.3.0/gems/konacha-4.0.0/lib/konacha/runner.rb:7:in `start'
/Users/andrewculver/.rvm/gems/ruby-2.3.0/gems/konacha-4.0.0/lib/konacha.rb:21:in `run'
/Users/andrewculver/.rvm/gems/ruby-2.3.0/gems/konacha-4.0.0/lib/tasks/konacha.rake:9:in `block (2 levels) in <top (required)>'
/Users/andrewculver/.rvm/gems/ruby-2.3.0/gems/rake-11.3.0/exe/rake:27:in `<top (required)>'
/Users/andrewculver/.rvm/gems/ruby-2.3.0/bin/ruby_executable_hooks:15:in `eval'
/Users/andrewculver/.rvm/gems/ruby-2.3.0/bin/ruby_executable_hooks:15:in `<main>'

More than happy to try and help debug this further, and I suspect it might have something to do with capybara_webkit, but wanted to first check whether there is something obvious going on here.