Haskell - 使用自定义预处理器打包 cabal 包答案

【问题标题】：Haskell - Packaging cabal package with custom preprocessorsHaskell - 使用自定义预处理器打包 cabal 包
【发布时间】：2013-04-21 20:10:42
【问题描述】：

我已经实现了一个自定义预处理器，它从 *.tpl 文件创建 *.hs 文件。它在Setup.hs 中使用Build-Type: Custom 指定。一切正常，但我无法从中创建 tar.gz 包（使用 cabal sdist）。

Cabal 抱怨说它找不到预处理器生成的暴露模块。错误信息是

cabal: Error: Could not find module with any
suffix: ["gc","chs","hsc","x","y","ly","cpphs","hs","lhs"]

我怎样才能让 Cabal 知道该模块没有丢失，或者可能将 tpl 添加到已知的文件扩展名，或者其他什么？

【问题讨论】：

你能给我们看看你的.cabal文件吗？
我认为您需要编写一个自定义 sdist 挂钩，然后使用 Setup sdist 构建 tarball（因为 github.com/haskell/cabal/issues/403）。
实际上，我认为这只需运行Setup sdist即可。

标签： haskell cabal cabal-install

【解决方案1】：

这是a known issue with cabal sdist。请改用./dist/setup/setup sdist。

这是一个例子：

$ cat preprocessor-test.cabal 
name:                preprocessor-test
version:             0.1.0.0
build-type:          Custom
cabal-version:       >=1.10
extra-source-files:  PreprocessorTest/*.prepro

library
  exposed-modules:     PreprocessorTest.PreprocessorTest
  build-depends:       base ==4.5.*
  -- hs-source-dirs:
  default-language:    Haskell2010

$ cat Setup.hs 
#!/usr/bin/env runhaskell

import Distribution.Simple
import Distribution.Simple.PreProcess
import Distribution.Simple.Utils
import Distribution.PackageDescription
import Distribution.Simple.LocalBuildInfo
import System.Cmd (rawSystem)
import System.FilePath ((</>))

main = let hooks = simpleUserHooks
           dummy = ("prepro", dummyPreprocessor)
       in defaultMainWithHooks hooks
          { hookedPreProcessors = dummy:knownSuffixHandlers  }

dummyPreprocessor :: BuildInfo -> LocalBuildInfo -> PreProcessor
dummyPreprocessor build local = PreProcessor {
  platformIndependent = True,
  runPreProcessor =
    mkSimplePreProcessor $ \inFile outFile verbosity -> do
      notice verbosity (inFile ++ " is being preprocessed to " ++ outFile)
      rawSystem "cp" [inFile, outFile]
      return ()
  }
$ cat PreprocessorTest/PreprocessorTest.prepro 
module PreprocessorTest.PreprocessorTest
       where

preprocessorTest :: Int
preprocessorTest = 1

$ cabal configure
Resolving dependencies...
[1 of 1] Compiling Main             ( Setup.hs, dist/setup/Main.o )
Linking ./dist/setup/setup ...
Configuring preprocessor-test-0.1.0.0...

$ cabal build    
Building preprocessor-test-0.1.0.0...
Preprocessing library preprocessor-test-0.1.0.0...
PreprocessorTest/PreprocessorTest.prepro is being preprocessed to
dist/build/PreprocessorTest/PreprocessorTest.hs
[1 of 1] Compiling PreprocessorTest.PreprocessorTest ( dist/build/PreprocessorTest/PreprocessorTest.hs, dist/build/PreprocessorTest/PreprocessorTest.o )
Registering preprocessor-test-0.1.0.0...

$ ./dist/setup/setup sdist
Distribution quality errors:
No 'synopsis' or 'description' field.
The 'license' field is missing or specified as AllRightsReserved.
Distribution quality warnings:
No 'category' field.
No 'maintainer' field.
Note: the public hackage server would reject this package.
Building source dist for preprocessor-test-0.1.0.0...
Preprocessing library preprocessor-test-0.1.0.0...
PreprocessorTest/PreprocessorTest.prepro is being preprocessed to
dist/src/sdist.-6767/preprocessor-test-0.1.0.0/dist/build/PreprocessorTest/PreprocessorTest.hs
Source tarball created: dist/preprocessor-test-0.1.0.0.tar.gz

$ tar tzf dist/preprocessor-test-0.1.0.0.tar.gz
preprocessor-test-0.1.0.0/
preprocessor-test-0.1.0.0/dist/
preprocessor-test-0.1.0.0/dist/build/
preprocessor-test-0.1.0.0/dist/build/PreprocessorTest/
preprocessor-test-0.1.0.0/dist/build/PreprocessorTest/PreprocessorTest.hs
preprocessor-test-0.1.0.0/Setup.hs
preprocessor-test-0.1.0.0/PreprocessorTest/
preprocessor-test-0.1.0.0/PreprocessorTest/PreprocessorTest.prepro
preprocessor-test-0.1.0.0/preprocessor-test.cabal

【讨论】：