haskell-src-exts fails to install with missing dependencies

[Duncan Coutts]

On Sun, 2010-05-30 at 08:05 +0100, Dominic Steintiz wrote:
> fourier:/home/dom1 # cabal upgrade haskell-src-exts
> > Resolving dependencies...
> > Downloading haskell-src-exts-1.9.0...
> > <command line>: cannot satisfy -package Cabal-1.8.0.2:
> >     Cabal-1.8.0.2-72f6eafc7def741b28f6ec75d2686d14 is unusable due to
> > missingor recursive dependencies:
> >       process-1.0.1.2-8b5308cb23fbdc3c2df27e298550937f
> >     (use -v for more information)
> > cabal: Error: some packages failed to install:
> > haskell-src-exts-1.9.0 failed during the configure step. The exception
> > was:
> > ExitFailure 1

Use ghc-pkg check to list broken packages. Unregister broken packages
and re-install the ones you need.

You may find you've got instances of core packages in your per-user
package db (e.g. process). Nuke those. Keep the global ones.

Oh, and don't use "cabal upgrade", it makes this sort of problem worse
by upgrading core packages. Use "cabal install" instead.

I'm going to nuke "cabal upgrade foo" and replace it with "cabal install
foo --upgrade-dependencies", which I think people will not use without
understanding what it means.

Duncan