gem_override_marker

https://github.com/be-agile/gem_override_marker

When you override a gem's method (e.g. with prepend) or copy a gem's view/partial and edit it, upstream changes on upgrade can silently break it. gem_override_marker lets you declare what each override is based on with a @gem-override marker, and generate the diff against upstream on demand, so you can efficiently re-apply your customization to the new version.