Right now environment variables are documented both in darcs help 
environment (see issue1455 and 2009-05 darcs-users archives) and in the 
user manual.  

Without a clear documentation policy, this duplication is harmful 
because (a) users don't know where to look and (b) darcs hackers don't 
know where to add documentation.

I get the impression that we're phasing out the TeX documentation on 
environment variables, perhaps replacing them with the text that Trent 
wrote for issue1455.  If this is the case, we need to update preproc (or 
the relevant scripts) to automatically write this help text into the 
manual so we can ditch the LaTeX copy.

As I understand it correctly, we're transitioning out of literate 
Haskell documentation for the user manual into something wiki hosted.
One thing that's not entirely clear to me is if the user manual will 
still have an autogenerated component via mechanisms like preproc.  See 
Trent's vision from March, http://irclog.perlgeek.de/darcs/2010-03-
02#i_2054957 (stop at 14:02)