How do I enable error logging in Rails production logs?

Question

I use Rails 5 for Unicorn. When I start visiting a specific page in my instance of my application, I get an error

We're sorry, but something went wrong. If you are the application owner check the logs for more information. 

When I look at my myproject / log / production.log, I see a request, but I won’t explain why the error occurred ...

 Started GET "/my_objects/search?utf8=%E2%9C%93&first_name=Dave&last_name=&my_object=&x=12&y=13" for 96.84.106.123 at 2017-12-29 15:34:20 -0500 Processing by my_objectsController#search as HTML Parameters: {"utf8"=>"✓", "first_name"=>"Dave", "last_name"=>"", "my_object"=>"", "x"=>"12", "y"=>"13"} Rendering my_objects/search.html.erb within layouts/my_object Rendered my_objects/_search.html.erb (1.3ms) 

How to include errors in my log file? The following describes how my registrar is configured in my file. /config/environments/production.rb ...

 Rails.application.configure do # Settings specified here will take precedence over those in config/application.rb. # Code is not reloaded between requests. config.cache_classes = true # Eager load code on boot. This eager loads most of Rails and # your application in memory, allowing both threaded web servers # and those relying on copy on write to perform better. # Rake tasks automatically ignore this option for performance. config.eager_load = true # Full error reports are disabled and caching is turned on. config.consider_all_requests_local = false config.action_controller.perform_caching = false # Enable Rack::Cache to put a simple HTTP cache in front of your application # Add `rack-cache` to your Gemfile before enabling this. # For large-scale production use, consider using a caching reverse proxy like # NGINX, varnish or squid. # config.action_dispatch.rack_cache = true # Disable serving static files from the `/public` folder by default since # Apache or NGINX already handles this. config.serve_static_files = ENV['RAILS_SERVE_STATIC_FILES'].present? # Compress JavaScripts and CSS. config.assets.js_compressor = :uglifier # config.assets.css_compressor = :sass # Do not fallback to assets pipeline if a precompiled asset is missed. config.assets.compile = false # Asset digests allow you to set far-future HTTP expiration dates on all assets, # yet still be able to expire them through the digest params. config.assets.digest = true # `config.assets.precompile` and `config.assets.version` have moved to config/initializers/assets.rb # Specifies the header that your server uses for sending files. # config.action_dispatch.x_sendfile_header = 'X-Sendfile' # for Apache # config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect' # for NGINX # Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies. # config.force_ssl = true # Use the lowest log level to ensure availability of diagnostic information # when problems arise. config.log_level = :debug # Prepend all log lines with the following tags. # config.log_tags = [ :subdomain, :uuid ] # Use a different logger for distributed setups. # config.logger = ActiveSupport::TaggedLogging.new(SyslogLogger.new) # Use a different cache store in production. config.cache_store = :memory_store, { size: 32.megabytes } # Enable serving of images, stylesheets, and JavaScripts from an asset server. # config.action_controller.asset_host = 'http://assets.example.com' # Ignore bad email addresses and do not raise email delivery errors. # Set this to true and configure the email server for immediate delivery to raise delivery errors. # config.action_mailer.raise_delivery_errors = false # Enable locale fallbacks for I18n (makes lookups for any locale fall back to # the I18n.default_locale when a translation cannot be found). config.i18n.fallbacks = true # Send deprecation notices to registered listeners. config.active_support.deprecation = :notify # Use default logging formatter so that PID and timestamp are not suppressed. config.log_formatter = ::Logger::Formatter.new # Do not dump schema after migrations. config.active_record.dump_schema_after_migration = false config.serve_static_files = true config.assets.compile = true # Raises error for missing translations # config.action_view.raise_on_missing_translations = true # Comment out the two lines withinn here so taht queries can be seen in the console config.after_initialize do ActiveRecord::Base.logger = Rails.logger.clone ActiveRecord::Base.logger.level = Logger::INFO end config.logger = ActiveSupport::Logger.new(config.paths['log'].first, 1, 50 * 1024 * 1024) # This is the classpath where we expect to find JAR files that will help decode Word documents. config.java_class_path = "/usr/java/share/poi-3.16/poi-3.16.jar:/usr/java/share/poi-3.16/poi-ooxml-3.16.jar:/usr/java/share/poi-3.16/poi-ooxml-schemas-3.16.jar:/usr/java/share/poi-3.16/ooxml-lib/xmlbeans-2.6.0.jar:/usr/java/share/poi-3.16/poi-scratchpad-3.16.jar:/usr/java/share/poi-3.16/lib/commons-collections4-4.1.jar:." end