Emacs integration - an overview

[Dan Christensen]

I'm trying to get the emacs mercurial support working for me in 
Gnu Emacs.  I'm using hg tip from a few minutes ago (version
31dcaf9123ba), and I get either 

  abort: /home/jdc/math/me/CayleyDickson/ not under repository root

if I do a global command, or

  vc-ensure-vc-buffer: File /home/jdc/math/me/CayleyDickson/python/todo is not under version control

if I do a local command.  The repository directory is in
/home/jdc/math/me/CayleyDickson/.hg and the file .../python/todo
*is* under hg's control...

Earlier I was using Debian's hg 0.6b, with a version of mercurial.el
from a few days ago, and mercurial.el at least could tell that the
file was under version control (Hg showed up in the mode line).
But there were other problems, probably because 0.6b was too old.

hg-binary is /usr/local/bin/hg, which is the version I installed from
source.  (hg-root) gives '/home/jdc/math/me/CayleyDickson/'.  The
variable hg-root which is defvar'd in the mercurial.el file is unset,
though.  I tried manually setting it, but that didn't help.

Any thoughts on how I can help debug this?  I have decent e-lisp
skills.

Dan