[Haskell-beginners] Broken packages after upgrading to Ubuntu 13.04

[Daniel Fischer]

On Tuesday 30 April 2013, 10:05:28, Johannes Engels wrote:
> Hello, using the OS-specific Haskell packages of the Ubuntu distribution,
> I have some cabal packages installed in addition, e.g. hmatrix etc.
> After an upgrade to Ubuntu 13.04 most of these cabal packages are broken
> because some dependencies do not exist anymore or have been upgraded also,
> respectively. With ghc-pkg check I get messages like
> 
> There are problems in package hmatrix-0.14.0.1:
>    dependency "array-0.4.0.0-0b32f6f98c0297dbb0e5cfc0087bd1f0" doesn't exist
> dependency "base-4.5.0.0-c8e7184681d410015e93df85fc49e9dd" doesn't exist
> ....
> 
> Actually now array-0.4.0.1 is installed etc.
> What is the recommended way to repair this? Should I do a --reinstall of
> the cabal packages (which should mostly also work with the upgraded
> dependencies)? Any hint would be welcome!

You have a different version of array, so you most likely have a different 
version of GHC. That means you have to rebuild your cabal packages.

Check with the --dry-run flag first,

$ cabal install world --dry-run

whether cabal finds a consistent install plan.

But that ghc-pkg check searches the package-db of the previous version 
irritates me. It should see that that is from an older version and ignore it.

> Best regards
> Johannes Engels