After upgrading from Redis gem v4.8.0 to v5.0.2 we got the following error on Heroku.
Our Redis URLs take the form redis://h:[email protected]:12345
Resque.schedule = YAML.load_file(Rails.root.join("config", "resque_schedule.yml"))
RedisClient::CommandError: ERR wrong number of arguments for 'auth' command
Reverting to Redis v4.8.0 corrects the issue.