[Haskell-cafe] Cannot install any packages after upgrading to GHC 8.0.1

[Gershom B]

On July 11, 2016 at 3:49:46 AM, Magicloud Magiclouds (magicloud.magiclouds at gmail.com) wrote:
> Hi,
> I update my GHC to 8.0.1 and failed to install any packages since then.
> If I use cabal, I got 'installed package info from too old version of Cabal
> (key field does not match id field)' for every package.
> If I use Setup.hs, I got 'Configuring Cabal-1.24.0.0...
> Setup.hs: ghc-pkg dump failed'.
> What should I do? Googling did not get me an answer.

The former error can occur if your cabal binary is too old. You can download a newer cabal binary from: https://www.haskell.org/cabal/download.html

If the latter error persists, then perhaps your ghc-pkg was not updated along with your ghc?

—gershom