Hi all, I've just asked this on SO as well ( http://stackoverflow.com/questions/9301122/haskell-cabal-package-indirectly-...), 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 - it "indirectly depends on multiple versions of the same package." However, cabal does not name the package that it claims cabal-dev requires multiple versions of. - Cabal-1.14.0 has "missing or recursive dependencies", specifically somehow involving array-0.4.0.0 and containers-0.4.2.1. A graph of the dependencies it lists confirms that neither of these claims are true (or the dependencies it lists are false or incomplete): [image: 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