I'm using OfflineIMAP and Dovecot plus notmuch from git's current HEAD.  I do:

 notmuch count tag:unread
 4

But doing "M-x notmuch" in emacs it shows

  44,895 unread

Does anyone know what the discrepancy may be due to?

If it matters, I'm also trying to get GNUS to play nice with this
setup and having troubles w.r.t. GNUS always wanting to retrieve all
articles, even ones that are "ancient" (marked with "O").  It may be
unrelated.

Thanks,
-Brett.