使用Cygwin编译Haskell代码的问题求助

Hey there! Let's work through this GHC issue you're hitting in Cygwin while following Learn You a Haskell for Great Good. Here are some targeted fixes to get your hello world program compiling smoothly:

1. Verify GHC is in Cygwin's PATH #

Cygwin might not be able to find the ghc command because the WinGHCi installation path isn't added to its environment variables.

• First, check if Cygwin can locate GHC by running:

  which ghc
  

• If you get no output, add your GHC bin directory to Cygwin's PATH temporarily with:

  export PATH="$PATH:/cygdrive/c/Program Files/Haskell Platform/[your-ghc-version]/bin"
  

  Replace [your-ghc-version] with the actual version number in your installation (like 8.10.7). To make this permanent, add the same line to your ~/.bashrc file in Cygwin.

2. Double-Check Your File Path in Cygwin #

Cygwin uses Unix-style paths instead of Windows' drive letters. For example, C:\Users\YourName\Documents becomes /cygdrive/c/Users/YourName/Documents in Cygwin.

• Navigate to your program's directory using cd:

  cd /cygdrive/c/[your-windows-path-to-helloworld]
  

• Confirm the file exists with ls, then run the compile command again:

  ghc --make helloworld
  

3. Try Using WinGHCi's Built-In Terminal #

WinGHCi comes with a pre-configured terminal that already has the correct GHC environment set up, which avoids Cygwin compatibility headaches.

• Open WinGHCi, then switch to your program's directory with:

  :cd C:\Users\YourName\Path\To\Your\File
  

• Compile and run the program directly with:

  :! ghc --make helloworld
  :main
  

4. Check for GHC Version Conflicts #

If you've installed GHC both via WinGHCi and Cygwin's package manager, conflicting versions can cause errors.

• In Cygwin, run ghc --version
• In WinGHCi, run :version
• If the versions don't match, uninstall the Cygwin-installed GHC (using apt-cyg remove ghc) and stick with the WinGHCi version for consistency.

内容的提问来源于stack exchange，提问作者user65526