[Haskell-cafe] Re: Announce: Significant performance improvements for Data.Map

[Johannes Waldmann]

>      darcs get http://code.haskell.org/~dons/code/containers/

I was giving this a try, and this soon hosed ghc (6.12.3):

* (starting from a pristine ghc, from a binary package)
* cabal install for containers-0.4.0.0 (the above package)
* then cabal install for some package that uses template-haskell
* then ghc-pkg check: There are problems in package ghc-6.12.3:
  dependency "template-haskell-2.4.0.1-e9e9c63092746bd4a3f64cc37ddb1e06" doesn't
exist

I seems template-haskell.cabal contains "containers"
(without any version constraints)  as a dependency,
so "cabal install" goes to rebuild this 
(since it prefers the fresh containers version).

this looks like 
http://hackage.haskell.org/trac/hackage/ticket/675
but not quite.

could "cabal install" (or "ghc-pkg register"?)
please please refuse to install a package that would break others
(especially, if "others = ghc").

what's the proper way to use containers-0.4 now?
(I was going to suggest "can you just put it on hackage"
but given the above, this would probably be a bad idea.)
I plug the new "containers" into a ghc source tree?

J.W.