module Sprockets::Processing

def deprecate_legacy_processor_interface(interface)
  msg = "You are using a deprecated processor interface #{ interface.inspect }.\n" +
  "Please update your processor interface:\n" +
  "https://github.com/rails/sprockets/blob/master/guides/extending_sprockets.md#supporting-all-versions-of-sprockets-in-processors\n"
  Deprecation.new([caller[3]]).warn msg
end