windows - 在 Haskell 中，如何在 Windows 上安装编码包？

Question

我是 haskell 的新手，我正在做一个简单的项目，但我需要运行 cabal install encoding。但是，当我这样做时，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 .说的最重要的是

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，我在 Cygwin 网站上查看了 langinfo.h 的位置。 Turns out it comes with the default install of Cygwin.这是它的路径:

usr/include/langinfo.h

So I installed Cygwin ，(实际上我已经安装了它)然后我像这样运行 cabal install:

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

注册包没有问题。

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更新

虽然这确实允许您注册包，但您不能使用它。当我尝试 GHCi 时，出现了这个错误:

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

我现在又卡住了。

更新2

我在 IRC 上从一位名叫 fryguybob 的先生那里得到了一些帮助。这是另一种安装方式:cabal install encoding -f-systemencoding。这对我有用