gerrit-download

This is a mode that will download a review from gerrit using the
`git-review' software and run show the diff for that changes.

This is using magit and the `magit-repo-dirs` variable to download
the change into.

With gnus add a hook like this
(add-hook 'gnus-startup-hook 'gerrit-download-insinuate-gnus)
in your init file and use the 'v' key to have it automatically
parse the email and show the diff.