Add a command-line option to the darcs-all script to specify the darcs repository to use
darcs-all script currently assumes that it is being run from the top level of a darcs repository. It uses the repository location stored in
_darcs/prefs/defaultrepo to determine from where to get the other repositories that GHC depends on.
The assumption that the script is being run from a darcs repository is unnecessary and is a hindrance to people who wish to use the git mirror of the GHC repository. To make this script more flexible, and to allow git users to use the repository without having to hack this script, I propose adding to the script a
-r option, which itself takes as an argument the location of a darcs repository from which to get GHC's dependencies.
This option would be useful for darcs users as it would allow them to get, pull, or push from any darcs repository they wish. It would also be useful to git users, as it would allow them to quickly get started working on GHC by using the command
./darcs-all -r http://darcs.haskell.org/ghc get