Angelo Graziosi wrote:
Underfull \hbox (badness 10000) in paragraph at lines 328--336
This is not a bug. We address issues related to line breaks just before
the release. It is pointless to work on them before, because they change
all the time. And when we do, the manual is typeset for printing as a
book by the FSF on small paper size. In my experience, it is impossible
to make line-breaks look nice on more than one paper size for a 500+
page manual, and pointless to even try. So I for one am not going to
spend any time on this.