无法安装http-conduit-1.9.6

Question

我正在尝试安装http-conduit-1.9.6，并且运行cabal install http-conduit-1.9.6会出现以下错误：

Network/HTTP/Conduit/Request.hs:43:8:
    Could not find module `Network.URI'
    It is a member of the hidden package `network-2.5.0.0'.
    Perhaps you need to add `network' to the build-depends in your .cabal file.
    It is a member of the hidden package `network-2.4.1.2'.
    Perhaps you need to add `network' to the build-depends in your .cabal file.
    Use -v to see a list of the files searched for.
Failed to install http-conduit-1.9.6
World file is already up to date.
cabal: Error: some packages failed to install:
http-conduit-1.9.6 failed during the building phase. The exception was:
ExitFailure 1

我已经安装了network-2.5.0.0和network-2.4.1.2，ghc-pkg list network的输出是：

/var/lib/ghc/package.conf.d
/root/.ghc/x86_64-linux-7.6.3/package.conf.d
   network-2.4.1.2
   network-2.5.0.0
   network-2.6.0.2

我是Haskell的新手，我现在确定是否有两个存储库可能是个问题。我的工作平台是Ubuntu 14.04，GHC 7.6.3和cabal 1.20。