This is meant to fix bug#25759 “Should 'surf' depend on 'xprop' and
'dmenu'?“:

https://lists.gnu.org/archive/html/bug-guix/2017-02/msg00054.html

I'm not sure if we really want this patch to be merged because there was
not much of a discussion on this proposal on the mailing list.

Also, I hope I'm sending it to the right mailing-list. I'm quite
confused by all the mailing-lists and bug-trackers.