The plugin initialization deprecation message added in #4629 is missing the name of the plugin affected, as the "called from" information doesn't indicate the source.

Initializing plugins using :after => :finish_hook inyour engine is deprecated. It delays the load of some assets in Sprockets. If you are the plugin author, please change your plugin engine initializer to use:before => :finisher_hook or after_initialize. (called from ...)