Haskell cabal 对文件和模块名称感到困惑

Question

在我的 haskell 项目中，我有以下目录结构(缺少一些条目，但与此问题无关)

- quanthas
   - quanthas.cabal
   - src/
      - QuantHas/
         - Settings.hs

我的 Settings.hs 文件包含此模块头

module QuantHas.Settings(module QuantHas.Settings) where

我的 cabal 文件如下所示

Name:               QuantHas
Version:            0.0
Description:
    QuantHas project is an attempt to port QuantLib to Haskell keeping the functional flavor of Haskell.
License:            BSD3
License-file:       LICENSE
Build-Type:         Simple
Cabal-Version:      >=1.10

Library
  Build-Depends:    base >= 3 && < 5, array >= 0.2
  Exposed-modules:  QuantHas.Time.Frequency
                QuantHas.Time.TimeUnit
                QuantHas.Time.Period
                QuantHas.Time.Date
                QuantHas.Time.DayCounter
                QuantHas.Time.BusinessDayConvention
                QuantHas.Time.Calendar
                QuantHas.Time.Calendars.UnitedKingdom
                QuantHas.Time.Schedule
                QuantHas.Settings
                QuantHas.Require
  default-language: Haskell2010                 
  hs-source-dirs:   src
  --  ghc-options:      -Wall

test-suite QuantHas-tests
  type: exitcode-stdio-1.0
  hs-source-dirs: testsuite
  main-is: Tests.hs
  default-language: Haskell2010  

当我执行时

cabal install --enable-tests

我收到这条消息

src/Quanthas/Settings.hs:17:8: error:
   File name does not match module name:
   Saw: ‘QuantHas.Settings’
   Expected: ‘Quanthas.Settings’

这似乎是错误的。然而，如果我们按照 cabal 的预期去做呢？所以现在的Settings.hs模块头是

module Quanthas.Settings(module Quanthas.Settings) where

cabal 现在说

src/QuantHas/Settings.hs:17:8: error:
   File name does not match module name:
   Saw: ‘Quanthas.Settings’
   Expected: ‘QuantHas.Settings’

正是在这个点上，我放弃了并转向SO。谁能帮我理解发生了什么？

版本信息: 平台:运行 MacOS 10.12.3 的 Macbook Pro haskell :8.0.1 cabal :1.24.0.0

谢谢!

Answer 1

问题在于不同模块中的导入语句之一存在拼写错误。由于您使用的是不区分大小写的文件系统 (OS X)，GHC 能够找到模块内容，但在检查模块头时发现它与导入语句不匹配并出错。