Added a fake guard that simply breaks (for tests purpose)

Guardfile

@@ -1,5 +1,19 @@
-guard('rspec', :version => 2) do
-  watch(%r{^spec/(.*)_spec\.rb})
-  watch(%r{^lib/(.*)\.rb})       { |m| "spec/#{m[1]}_spec.rb" }
+guard :rspec, :version => 2 do
+  watch(%r{^spec/.+_spec\.rb$})
+  watch(%r{^lib/(.+)\.rb$})     { |m| "spec/#{m[1]}_spec.rb" }
   watch('spec/spec_helper.rb')  { "spec" }
 end
+
+require 'guard/guard'
+
+module ::Guard
+  class Breaking < ::Guard::Guard
+    def run_all
+      raise "Fool !"
+    end
+  end
+end
+
+group "exceptional" do
+  guard :breaking
+end