我尝试按如下方式设置yesod项目：
mkdir sample_blog
curl -o cabal.config www.stackage.org/nightly/cabal.config
cabal install alex happy yesod-bin
但是，我收到以下错误：
Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: Cabal (user goal)
rejecting: Cabal-1.18.1.4/installed-d6c... (global constraint requires
==1.18.1.3)
trying: Cabal-1.18.1.3/installed-476...
trying: yesod-bin-1.4.2 (user goal)
next goal: ghc (dependency of yesod-bin-1.4.2)
rejecting: ghc-7.8.3/installed-1d5... (conflict:
Cabal==1.18.1.3/installed-476..., ghc => Cabal==1.18.1.4/installed-d6c...)
Dependency tree exhaustively searched.
Note: when using a sandbox, all packages are required to have consistent
dependencies. Try reinstalling/unregistering the offending packages or
recreating the sandbox.
我使用自制软件安装GHC和cabal-install。 版本：
$ ghc --version
The Glorious Glasgow Haskell Compilation System, version 7.8.3
$ cabal --version
cabal-install version 1.20.0.4
using version 1.20.0.3 of the Cabal library
答案 0 :(得分：2)
似乎自制软件已经修补了标准的GHC安装，因为它提供的是与官方GHC不同版本的Cabal库。我不知道为什么会这样。一个快速的解决方法是从Cabal中删除cabal.config行。你可以打开一个针对Stackage的问题吗？我想了解为什么会发生这种情况。