Hi all,

I've just asked this on SO as well (http://stackoverflow.com/questions/9301122/haskell-cabal-package-indirectly-depends-on-multiple-versions-of-the-same-pack), but to repeat the question:

After clearing out all of my cabal installed packages, I ran this following session:

$ cabal update
Downloading the latest package list from hackage.haskell.org
james@bast:~/.cabal/packages$ cabal install cabal-dev
Resolving dependencies...
Downloading cabal-dev-0.9.1...
[1 of 1] Compiling Main             ( /tmp/cabal-dev-0.9.124882/cabal-dev-0.9.1/Setup.hs, /tmp/cabal-dev-0.9.124882/cabal-dev-0.9.1/dist/setup/Main.o )
Linking /tmp/cabal-dev-0.9.124882/cabal-dev-0.9.1/dist/setup/setup ...
Configuring cabal-dev-0.9.1...
Warning: This package indirectly depends on multiple versions of the same
package. This is highly likely to cause a compile failure.
package containers-0.4.2.1 requires array-0.4.0.0
package Cabal-1.14.0 requires array-0.4.0.0
package text-0.11.1.13 requires array-0.4.0.0
package deepseq-1.3.0.0 requires array-0.4.0.0
package containers-0.4.2.1 requires array-0.4.0.0
package HTTP-4000.2.2 requires array-0.4.0.0
package cabal-dev-0.9.1 requires containers-0.4.2.1
package Cabal-1.14.0 requires containers-0.4.2.1
package template-haskell-2.7.0.0 requires containers-0.4.2.1
Building cabal-dev-0.9.1...
Preprocessing executable 'ghc-pkg-6_8-compat' for cabal-dev-0.9.1...
<command line>: cannot satisfy -package-id Cabal-1.14.0-4af45d3c8d10dc27db38ae0e7e5a952b: 
    Cabal-1.14.0-4af45d3c8d10dc27db38ae0e7e5a952b is unusable due to missing or recursive dependencies:
      array-0.4.0.0-46f61f5fd9543ebf309552ef84dccc86 containers-0.4.2.1-98f9aa15f9c08b13673dc9d89385f449
    (use -v for more information)
cabal: Error: some packages failed to install:
cabal-dev-0.9.1 failed during the building phase. The exception was:
ExitFailure 1
$ 

So the reason I can't install cabal-dev is apparently either that

A graph of the dependencies it lists confirms that neither of these claims are true (or the dependencies it lists are false or incomplete):

claimed dependency graph of cabal-dev-0.9.1

So: what am I missing? Who or what is incorrect: me, cabal, or one or more packages?

I am running:

$ cabal --version
cabal-install version 0.10.2
using version 1.10.1.0 of the Cabal library 
$ ghc --version
The Glorious Glasgow Haskell Compilation System, version 7.4.1
$

Any help with this would be greatly appreciated.  I get errors from cabal fairly often and I usually end up giving up because I don't understand the error.


James