On Thu, Nov 25, 2010 at 2:52 AM, Iain Alexander <[email protected]> wrote: > <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 �[email protected] > > _______________________________________________ > Haskell-Cafe mailing list > [email protected] > http://www.haskell.org/mailman/listinfo/haskell-cafe >
Maybe it helps if special-functors gets an upper bound on its mtl dependency: mtl < 2. BTW what is you ghc --version? Because I have no problems fetching mtl-2: $ ghc --version The Glorious Glasgow Haskell Compilation System, version 6.12.1 $ cabal --version cabal-install version 0.8.0 using version 1.8.0.2 of the Cabal library $ cabal fetch mtl==2.0.0.0 Resolving dependencies... Downloading mtl-2.0.0.0... Regards, Bas _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
