[Haskell-cafe] Why does cabal unnecessarily reinstall dependencies?

[Nicolas Maupu]

On Mon, Nov 22, 2010 at 22:26, Martijn van Steenbergen
<martijn at van.steenbergen.nl> wrote:
> Hello cafe,
Hello

>
> When I want to locally install my own package through "cabal install" it
> tries to reinstall dependencies convertible-1.0.9.1, HDBC-2.2.6.1 and
> HDBC-mysql-0.6.3 even though they are already installed (and work fine). Why
> does it do this?
>
> cabal-install version 0.8.2
> using version 1.8.0.2 of the Cabal library
> Mac OS Leopard
>

I had exactly the same problem on Mac OS snow leopard.
My cabal package was just broken, wrongly installed, or whatever (I
installed it from mac ports).
The solution is to deinstall it and to install it from tarball as
explained here :
<http://jan.varwig.org/archive/getting-cabal-to-run-on-mac-os-x-leopard>