• Be aware when using the app from the config.ru file is used (the default option) that the Rack::Builder.parse_file seems to require files even if they have already been required, so make sure your boot files are idempotent.

• If the match results don't make sense, check that your Content-Type header is set - the matcher used depends on the Content-Type. If the Content-Type doesn't match "application/.*json", then it will be using a text matcher, which will do an exact text match.

• Try using a different diff formatter. Different people find the different formats easier to interpret.

Check the logs in log/.log for more information that you will see in the UI.

If pact:verify is failing with an exception other than a normal "match" failure, but you can't see enough of the backtrace to diagnose the issue, you can turn the full backtrace display on by adding BACKTRACE=true to the rake pact:verify command (you'll probably want to use the PACT_DESCRIPTION and PACT_PROVIDER_STATE environment variables too so that you don't have to trawl through every backtrace for every interaction in your pact at once).

$ bundle exec rake pact:verify BACKTRACE=true

Your pact_helper.rb file is most likely being required twice.