I think it was a good idea of droundy's to leave global cache [1] default to off
in darcs 2.0.0, but I am beginning to think that it might be a good idea for it
to be on by default in darcs 2.0.1.

Nowadays, it is not unusual for applications to use up space in a ~/.appname
directory, provided that they so state in the manual and ideally at "install
time" or "setup time" in the user-visible output.

Darcs-2 has very good performance nowadays, and performing well in more
different use cases, as I think a global cache achieves, by default, would be a
welcome addition.

(Indeed, for the use case of doing a full darcs get over the network using
hashed-format repositories [2], it already performs so well without a global
cache that adding a global cache hardly helps.  I guess this shows that we
should measure before we decide.) 

[1] http://darcs.net/manual/node5.html#SECTION00510000000000000000
[2] http://lists.osuosl.org/pipermail/darcs-users/2008-April/011783.html

Just to note my own personal experience: I've been steadily darcs getting and
pulling various stuff since darcs-2 was released, as is my wont, and I greatly
appreciate the speed increase. 

Currently, .darcs uses up 35M. In comparison, my .saves/ directory for Emacs
used 300M - until I deleted the largest ten backups and ran a duplicate-file
utility over it and managed to shrink it down to a mere 188M. In further
comparison, .wine is 1.7G, .ccache is 139M (I'm not even sure what that is), and
.mozilla is 97M.

So while it certainly is a worthwhile concern that users might be upset or
hostile about darcs caching stuff behind their backs, I don't think it'll be a
problem: it comes with a clear benefit, and is relatively modest compared to
some things.

This sounds reasonable to me.

I hope the duplicate file utility you used was
http://pypi.python.org/pypi/dupfilefind
  ;-)

Patch submitted to darcs-user for review.

The following patch updated the status of issue0839 to be resolved:

* resolve issue0839: enable global cache by default 
Ignore-this: 50deab104a57c707bfaf4e00a00c69cb