我该怎么安装fay？

Question

我运行的是ubuntu 13.10，安装fay有困难。我使用sudo apt-get install haskell-platform安装了haskell。我尝试cabal install fay并收到以下消息：

$ cabal install fay
Resolving dependencies...
Configuring type-eq-0.4.2...
cabal: The program cpphs is required but it could not be found.
Failed to install type-eq-0.4.2
cabal: Error: some packages failed to install:
fay-0.20.0.0 depends on type-eq-0.4.2 which failed to install.
haskell-names-0.3.3.2 depends on type-eq-0.4.2 which failed to install.
type-eq-0.4.2 failed during the configure step. The exception was:
ExitFailure 1

我试过安装cpphs，但我已经安装了它。

$ cabal install cpphs
Resolving dependencies...
All the requested packages are already installed:
cpphs-1.18.4
Use --reinstall if you want to reinstall anyway.

最后，我尝试了自己安装type-eq，并期望它依赖于cpphs。

$ cabal install type-eq
Resolving dependencies...
Configuring type-eq-0.4.2...
cabal: The program cpphs is required but it could not be found.
Failed to install type-eq-0.4.2
cabal: Error: some packages failed to install:
type-eq-0.4.2 failed during the configure step. The exception was:
ExitFailure 1

我该怎么办？提前谢谢你的帮助。

Answer 1

根据对原帖子的评论：

1. cabal抱怨找不到已经安装的cpphs
2. which cpphs说找不到命令
3. 这意味着cpphs不在shell的搜索路径中。
4. 将~/.cabal/bin添加到PATH可用于解决此问题