用Cabal安装HTF时出现故障

Question

我想安装HTF。不过我cabal install HTF后，我得到这个：

Resolving dependencies... 
Configuring HTF-0.10.0.7... 
Warning: This package indirectly depends on multiple versions of the same 
package. This is highly likely to cause a compile failure. 
package regex-base-0.93.2 requires mtl-2.0.1.0 
package aeson-0.6.0.2 requires mtl-2.1.2 
package HTF-0.10.0.7 requires mtl-2.1.2 
package mtl-2.0.1.0 requires transformers-0.2.2.0 
package transformers-base-0.4.1 requires transformers-0.3.0.0 
package mtl-2.1.2 requires transformers-0.3.0.0 
package monad-control-0.3.1.4 requires transformers-0.3.0.0 
Building HTF-0.10.0.7... 
Preprocessing library HTF-0.10.0.7... 
ghc: could not execute: cpphs 
cabal: Error: some packages failed to install: 
HTF-0.10.0.7 failed during the building phase. The exception was: 
ExitFailure 1 

我试图安装其他版本，但已经得到了不同的问题。例如， 与cabal install 'HTF <= 0.1'我得到如下：

Resolving dependencies... 
Downloading QuickCheck-1.2.0.1... 
Configuring QuickCheck-1.2.0.1... 
Building QuickCheck-1.2.0.1... 
Preprocessing library QuickCheck-1.2.0.1... 
[1 of 8] Compiling Test.QuickCheck (Test/QuickCheck.hs, dist/build/Test/QuickCheck.o) 
[2 of 8] Compiling Test.QuickCheck.Batch (Test/QuickCheck/Batch.hs, dist/build/Test/QuickCheck/Batch.o) 
[3 of 8] Compiling Test.QuickCheck.Utils (Test/QuickCheck/Utils.hs, dist/build/Test/QuickCheck/Utils.o) 
[4 of 8] Compiling Test.QuickCheck.Poly (Test/QuickCheck/Poly.hs, dist/build/Test/QuickCheck/Poly.o) 
[5 of 8] Compiling Debug.QuickCheck.Poly (Debug/QuickCheck/Poly.hs, dist/build/Debug/QuickCheck/Poly.o) 
[6 of 8] Compiling Debug.QuickCheck.Utils (Debug/QuickCheck/Utils.hs, dist/build/Debug/QuickCheck/Utils.o) 
[7 of 8] Compiling Debug.QuickCheck (Debug/QuickCheck.hs, dist/build/Debug/QuickCheck.o) 
[8 of 8] Compiling Debug.QuickCheck.Batch (Debug/QuickCheck/Batch.hs, dist/build/Debug/QuickCheck/Batch.o) 
Registering QuickCheck-1.2.0.1... 
Installing library in /home/xxx/.cabal/lib/QuickCheck-1.2.0.1/ghc-7.4.1 
Registering QuickCheck-1.2.0.1... 
Downloading HTF-0.1... 
Configuring HTF-0.1... 
Building HTF-0.1... 
Preprocessing library HTF-0.1... 
[1 of 8] Compiling Test.Framework.Utils (Test/Framework/Utils.hs, dist/build/Test/Framework/Utils.o) 
[2 of 8] Compiling Test.Framework.Process (Test/Framework/Process.hs, dist/build/Test/Framework/Process.o) 

Test/Framework/Process.hs:45:48: 
    Ambiguous type variable `a0' in the constraints: 
     (Show a0) 
     arising from a use of `show' at Test/Framework/Process.hs:45:48-51 
     (Control.Exception.Exception a0) 
     arising from a use of `Control.Exception.handle' 
     at Test/Framework/Process.hs:45:5-28 
    Probable fix: add a type signature that fixes these type variable(s) 
    In the expression: show e 
    In the first argument of `return', namely 
     `([], show e, error (show e))' 
    In the expression: return ([], show e, error (show e)) 
cabal: Error: some packages failed to install: 
HTF-0.1 failed during the building phase. The exception was: 
ExitFailure 1 

我也得到类似cabal install 'HTF <= 0.9'后的第一个成果。我试过ghc-pkg check，它给了我一个破包的列表。我重新安装了软件包，并重复尝试再次安装HTF，结果相同。

Answer 1

第一个问题是，你有regex-base建对mtl-2.0.1.0，从而

package regex-base-0.93.2 requires mtl-2.0.1.0 
package aeson-0.6.0.2 requires mtl-2.1.2 

HTF将取决于mtl多个版本。这很少起作用。

解决方案将是$ ghc-pkg unregister regex-base。如果ghc-pkg警告说会破坏其他软件包，那么您也必须重建这些软件包。如果手动执行的太多，可以考虑删除整个用户软件包-db（我希望这些软件包都是用户安装的，如果它们是全局安装的，则不能删除整个全局数据库）并重建所有内容与cabal install world。

在regex-base被删除后，什么都不会取决于mtl-2.0.1.0了，并且依赖关系不应该引起冲突;实际安装HTF之前，您应该检查与

cabal install HTF --dry-run 

如果仍然会有冲突，应该检测它们，你可以通过注销进一步包解决这些问题。

下一个问题是

ghc: could not execute: cpphs 

这看起来就好像你在你的PATH没有cpphs。要么您没有安装它，在这种情况下，您需要在安装HTF之前执行此操作，否则需要将其安装目录添加到PATH。