MTL Upgrade Problem

Dominic Steinitz dominic at
Sun Apr 17 15:40:40 CEST 2011

Daniel Fischer wrote:

Thanks for your quick reply.
> Rebuild the libraries that depend on mtl against mtl-2.
> $ ghc-pkg unregister mtl-
> should tell you which packages are affected, unregister those first (or 
> later after unregistering mtl- with --force) and reinstall them 
> against mtl-2. That doesn't work however, if any of them have a dependency 
> bound mtl < 2, so check that first (and even if they have no upper bound on 
> mtl, they may use the State or Writer, ... data constructors which aren't 
> available anymore since State etc. are now type synonyms).

I had already tried that and I knew I had a lot of packages depending on

> Or upgrade to ghc-7.0.3 and install everything fresh.
I feared this might be the answer :-) I'm about to buy a new computer so
this is probably the way I will go.

Many thanks for your help, Dominic.

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