(Copied from email sent to me by Juliusz...)

> Juliusz, I agree that it does seem like it would be a good idea to add some
> sort of umask config options to darcs.

  darcs apply --umask 0220 --group darcs-unstable

--user is not useful, unless you're running Darcs as root (although
I'm not sure... things like selinux might still find it useful).

It's possible to use posthooks to get a similar result.  In fact, with posthooks
you can use whatever script you want to compute the file permissions/group at
apply time.  I've done this with a repository I was managing and it worked
decently.  Perhaps it just needs to be in the manual.

A patch is pending for that (waiting for people to comment before pushing it).

  - I've discarded --uid and --gid, as the setgid directory hack is a simpler and
    more familiar solution to this problem;
  - --umask is implemented.

fixed in 1.0.9