Libraries in the repo

[Ian Lynagh]

I don't think the current situation has worked well, due to people
forgetting to push/send to the upstream repos, but if we use a prehook
script to stop people accidentally breaking the rules then (1) is
probably the best solution for the HEAD.

For stable branches, in order to avoid releasing with random darcs
versions, I think that it would be best to use released tarballs (2).


In order to migrate from GHC's bytestring fork, back to a repo
compatible with the upstream repo, we can't just switch the repos, as
you can't pull the new repo into an old checkout. There are some
additional complications, such as people who pull from local repos
rather than the darcs.haskell.org repos, which make this a little
fiddly.

I think we should:
* switch HEAD to use a released tarball of bytestring
* make darcs-all complain if libraries/bytestring is a checked out copy
  of the old repo (i.e. check to see if a particular patch ID is in it)
* wait a couple of months
* switch to using a darcs repo containing a subset of the upstream repo
  again

Hopefully during the couple of months everyone will update and use all
the repos they have lying around at least once, and thus will remove the
old checkout.


Thanks
Ian