Notmuch-devel contains the development libraries and header files for
Notmuch email program. These libraries and header files are
necessary if you plan to do development using Notmuch.
Install notmuch-devel if you are developing C programs which will use the
Notmuch library. You'll also need to install the notmuch package.
See also: notmuch, notmuch-git, notmuch-mutt.