-1. Install and use nmbug from notmuch version **0.18** or newer and
- perl module `Pod::Usage` (packaged as `perl-doc` in debian).
+0. Make sure that the whole [notmuch@notmuchmail.org mailing list
+ archive][archive] is available in your email database.
+
+ If you are missing messages which are tagged in the nmbug
+ repository, `nmbug status` will complain with U-prefixed lines and
+ you will have to jump through some hoops to create commits that
+ alter tags for those messages. Most other nmbug operation will be
+ unaffected.
+
+1. Install and use nmbug from notmuch version **0.19** or newer, and
+ either Python 2.7 or anything from the 3.x line.