cabal install cabal-install無法解決依賴關係

Question

我剛剛做了brew install haskell-platform並且它安裝了The Glorious Glasgow Haskell Compilation System，version 7.6.3。

$ cabal --version 
cabal-install version 1.16.0.2 
using version 1.16.0 of the Cabal library 

$ cabal update 
Downloading the latest package list from hackage.haskell.org 
Note: there is a new version of cabal-install available. 
To upgrade, run: cabal install cabal-install 

$ cabal install cabal-install 
Resolving dependencies... 
cabal: Could not resolve dependencies: 
trying: cabal-install-1.20.0.3 
rejecting: zlib-0.5.4.1, 0.5.4.0, 0.5.3.3, 0.5.3.2, 0.5.3.1, 0.5.2.0, 0.5.0.0, 
0.4.0.4, 0.4.0.3, 0.4.0.2, 0.4.0.1, 0.4, 0.3, 0.2 (global constraint requires 
installed instance) 

我不明白這是什麼問題，我第一次安裝了所有東西。

Answer 1

在安裝之前，我剛剛裝了一個壞的~/.cabal/config文件。

我做

$ rm -rf ~/.ghc ~/.cabal 
$ brew rm ghc 
$ brew rm haskell-platform 
$ brew install haskell-platform 

，並安裝好

$ cabal install cabal-install 
Resolving dependencies... 
Downloading Cabal-1.20.0.2... 
...