使用相互依赖的cabal管理两个库

Question

我有以下问题:

我有两个相互依赖的Haskell库,这两个库都是由cabal管理的.相应的cabal文件如下所示:

图书馆1:

name:           Lib1
version:        0.1
cabal-version:  >=1.2
build-type:     Simple
author:         Matthias

library
  hs-source-dirs:  src
  build-depends:   
               base >= 4,
               Lib2
  ghc-options:     -Wall
  exposed-modules:   <...>

图书馆2:

name:           Lib2
version:        0.1
cabal-version:  >=1.2
build-type:     Simple
author:         Matthias

library
  hs-source-dirs:  src
  build-depends:   
               base >= 4,
               Lib1
  ghc-options:     -Wall
  exposed-modules: <...>

使用cabal install作品安装其中一个库(此处为库2):

Resolving dependencies...
In order, the following will be installed:
Lib2-0.1 (reinstall)
Warning: Note that reinstalls are always dangerous. Continuing anyway...
Configuring Lib2-0.1...
Building Lib2-0.1...
Preprocessing library Lib2-0.1...
Registering Lib2-0.1...
Installing library in
C:\Users\Matthias\AppData\Roaming\cabal\Lib2-0.1\ghc-7.4.2
Registering Lib2-0.1...

但是尝试安装其他库(此处为库1)会cabal install导致依赖性错误:

Resolving dependencies...
cabal.exe: Could not resolve dependencies:
trying: Lib1-0.1 (user goal)
next goal: Lib2 (dependency of Lib1-0.1)
rejecting: Lib2-0.1/installed-aa4... (package is broken)

有没有办法处理两个相互依赖的库,这样我就不会出现依赖性错误,或者只是无法正确处理这种情况？

Answer 1

正如其他人所说,循环依赖永远不会在Cabal中起作用.编译具有循环依赖关系的模块是很困难的,但是包是一个无望的原因.

有时候它可能很烦人,但唯一真正的解决方案是找到一种方法来以某种方式打破循环依赖.