Recipes - Documentation - Twig - The flexible, fast, and secure PHP template engineDisplaying Deprecation Notices Deprecated features generate deprecation notices (via a call to the trigger_error() PHP function). By default, they are silenced and never displayed nor logged. To remove all deprecated feature usages from your templates, write and run a script along the lines of the following:
https://github.com/masakielastic/twig-ja/blob/master/02-Twig-for-Template-Designers.markdown
