Jump from notmuch to Gnus for nnml, nnfolder?

[Julien Cubizolles]

I'm trying to use notmuch with Gnus, Tassilo provided a way to jump from
a notmuch search result to the corresponding group in Gnus in
<87r5rk8cmt.fsf@thinkpad.tsdh.de>. However his setup addresses the case
of articles stored in a Maildir.

At the moment, my Gnus setup is a mess of Maildirs, nnml and nnfolder
backends (for "historical" reasons). I guess Tassilo's method could be
tweaked for all file-based backends like nnml but I'm not sure that
would be the case for nnfolder.

For those of you using notmuch with Gnus, what did you choose? Put all
your messages in a Maildir ?

Julien.