在Haskell中，如何在Windows上安装编码包？

Question

我是一个Haskell总新手，我正在做一个小项目，但我需要运行cabal install encoding。但是，当我这样做，它给了我这个错误：

Configuring encoding-0.6.7.2... 
setup.exe: Missing dependency on a foreign library: 
* Missing (or bad) header file: system_encoding.h 
This problem can usually be solved by installing the system package that 
provides this library (you may need the "-dev" version). If the library is 
already installed but in a non-standard location then you can use the flags 
--extra-include-dirs= and --extra-lib-dirs= to specify where it is. 
If the header file does exist, it may contain errors that are caught by the C 
compiler at the preprocessing stage. In this case you can re-run configure 
with the verbosity flag -v3 to see the error messages. 
cabal.exe: Error: some packages failed to install: 
encoding-0.6.7.2 failed during the configure step. The exception was: 
ExitFailure 1 

如何解决这个问题？

Answer 1

TL; DR：cabal install encoding -f-systemencoding

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I found a few forum posts on this topic。最重要的事情是

The missing header is langinfo.h - where it originates I don't know, as I don't have it with either Msys/MinGW or Cygwin and my Cygwin is pretty large these days.

从那里，我看了Cygn的网站langinfo.h是。 Turns out it comes with the default install of Cygwin.这是它的路径：

usr/include/langinfo.h 

So I installed Cygwin，（其实我已经有它安装），然后我跑小集团安装这样的：

cabal install encoding --extra-include-dirs='C:\cygwin\usr\include' 

注册的包没有问题。

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更新

虽然这让你注册包，你不能使用它。当我试图GHCi给我这个错误：

Loading package encoding-0.6.7.2 ... linking ... ghc: unable to load package `encoding-0.6.7.2' 

我现在再次卡住了。

更新2

我上了IRC一些帮助，从绅士命名fryguybob。这是另一种安装方法：cabal install encoding -f-systemencoding。这对我很有用