[Haskell-cafe] How to cabal fetch mtl==2.0.0.0?

[Iain Alexander]

<log>
F:\Util\Haskell>cabal fetch mtl==2.0.0.0
Resolving dependencies...
cabal: internal error: could not construct a valid install plan.
The proposed (invalid) plan contained the following problems:
The following packages are involved in a dependency cycle transformers-0.2.2.0,
special-functors-1.0, mtl-2.0.0.0

F:\Util\Haskell>cabal -V
cabal-install version 0.8.2
using version 1.8.0.2 of the Cabal library
</log>

Could someone please remind me of the correct incantation to make this work.  

(I observe that transformers-0.1.4.0 optionally (by cabal flag) depends on 
special-functors, and special-functors-1.0 depends on mtl.  So given that mtl-2 
no doubt depends on transformers, I can see the potential for confusion, but 
there presumably must be a way of breaking the (apparent) loop.)  

TIA,
Iain.
-- 
Iain Alexander      ia at stryx.demon.co.uk