After much thrashing about and getting some help from Jordi, I have
moved the hg.octave.org repos to a Digital Ocean server (the one that is
running the buildbot master) and off of Dreamhost. Now the update
script should be working again for our hg clone of gnulib.
Once that was done, I updated the gnulib subrepo on stable and default.
This task doesn't seem to be on the release checklist, but it probably
I also changed the subrepo address to use hg-new.octave.org. We can
switch it back once the DNS change for hg.octave.org makes its way
around the web.