I'm having an issue that has been discussed a long time ago:

http://lists.osuosl.org/pipermail/darcs-users/2005-August/008265.html

It seems like --set-scripts-executable still is not the default behavior and it
is quite hard to share these settings via _darcs/prefs/defaults since i cannot
add this to the version control (even removing the according entries from
_darcs/prefs/boring won't let me do it)

So i would like to propose making --set-scripts-executable a default.

manveru, 

Thanks for the wishlist request. We'll keep it in mind. It is being deferred for
now as we focus on the critical issues blocking the Darcs 2.0 release.

   Mark

Sounds like the best thing would be for somebody to submit a patch.

We discussed this during the 2010-03 Darcs hacking sprint in Zurich and 
decided to retain --no-set-scripts-executable as the default.

Sorry!
See http://wiki.darcs.net/DefaultSwitches for rationale