Haskell 是的，安装失败

我通常发现一半以上的大型软件包的cabal安装都失败了，这对新用户来说是一个致命的缺陷

这次我想安装YesSOD，有什么提示吗

> cabal install yesod
  ...
Loading package time-1.2.0.5 ...

GHCi runtime linker: fatal error: I found a duplicate definition for symbol
   _get_current_timezone_seconds
whilst processing object file
   C:\Users\guthrie\AppData\Roaming\cabal\time-1.2.0.5\ghc-7.4.1\HStime-1.2.0.5.o
This could be caused by:
   * Loading two different object files which export the same symbol
   * Specifying the same object file twice on the GHCi command line
   * An incorrect `package.conf' entry, causing some object to be
     loaded twice.
GHCi cannot safely continue in this situation.  Exiting now.  Sorry.

cabal: Error: some packages failed to install:
authenticate-1.3.1.1 depends on http-conduit-1.6.1.1 which failed to install.
http-conduit-1.6.1.1 failed during the building phase. The exception was:
ExitFailure 1
yesod-1.1.1.2 depends on yesod-core-1.1.2.1 which failed to install.
yesod-auth-1.1.1.1 depends on yesod-core-1.1.2.1 which failed to install.
yesod-core-1.1.2.1 failed during the building phase. The exception was:
ExitFailure 1
yesod-form-1.1.3 depends on yesod-core-1.1.2.1 which failed to install.
yesod-json-1.1.0 depends on yesod-core-1.1.2.1 which failed to install.
yesod-persistent-1.1.0 depends on yesod-core-1.1.2.1 which failed to install.

---

这很可能是由于尝试同时安装两个版本的time package而导致的。您能否尝试运行

cabal install yesod platform

并查看问题是否仍然存在

---

正如@Inaimathi所说，这可能是由于较旧版本的

阴谋集团所造成的。也许还可以尝试
cabal update&&cabal install cabal install
YesSOD使用的alex软件包版本与Haskell平台不同。除了ghc，我总是从发行版的包管理器安装alex和happy，然后使用cabal。或者，您可以始终使用

cabal update && cabal install alex happy
cabal install yesod-platform

这可能是您版本的
cabal
（或者可能是Windows版本的
cabal
）存在的问题。我刚刚从Debian Wheezy的
cabal 1.14.0
成功地运行了安装过程。C:\Users\me>cabal--版本cabal使用cabal Library的1.14.0版安装版本cabal 0.14.0谢谢，在此之前我刚刚更新了cabal安装。yesod平台的安装显示了14个可能会被破坏的东西，在“http-CONDUCTOR-1.6.1无法安装”上进行强制重新安装失败，并且尝试单独安装时表示可能会破坏另外61个东西。啊。我不确定我是否应该继续沿着多米诺骨牌的链条继续下去，强制重新安装会破坏这么多东西？？