yesodweb/yesod — pull request #755 by axel-angel (2014-06-12 15:30:55+00:00)
Title: Add RenderMessage to new generateFormGet' (deprecation of non-prime)

From discussion: https://groups.google.com/forum/#!topic/yesodweb/lWKFzJDOnnY
I've discussed with Michael, it seems the right way to go.

Someone can check whether my warnings make sense?