Missing of regex.h on Windows

[u2x1]

Log

2020-02-17 20:55:41.773663: [info] regex-posix > build
2020-02-17 20:55:41.773663: [debug] Run process within C:\Users\nutr1\AppData\Local\Temp\stack7508\regex-posix-0.96.0.0\: C:\sr\setup-exe-cache\x86_64-windows\Cabal-simple_Z6RU0evB_3.0.1.0_ghc-8.8.2.exe --builddir=.stack-work\dist\29cc6475 build --ghc-options " -fdiagnostics-color=always"
2020-02-17 20:55:42.100248: [info] regex-posix > Preprocessing library for regex-posix-0.96.0.0..
2020-02-17 20:55:42.374347: [warn] regex-posix > C:\Users\nutr1\AppData\Local\Temp\stack7508\regex-posix-0.96.0.0\Wrap.hsc:96:10: fatal error: regex.h: No such file or directory
2020-02-17 20:55:42.377341: [warn] regex-posix > compilation terminated.
2020-02-17 20:55:42.394314: [warn] regex-posix > compiling .stack-work\dist\29cc6475\build\Text\Regex\Posix\Wrap_hsc_make.c failed (exit code 1)
2020-02-17 20:55:42.489164: [warn] regex-posix > command was: C:\Users\nutr1\AppData\Local\Programs\stack\x86_64-windows\ghc-8.8.2\lib\../mingw/bin\gcc.exe -c .stack-work\dist\29cc6475\build\Text\Regex\Posix\Wrap_hsc_make.c -o .stack-work\dist\29cc6475\build\Text\Regex\Posix\Wrap_hsc_make.o -D__GLASGOW_HASKELL__=808 -Dmingw32_BUILD_OS=1 -Dx86_64_BUILD_ARCH=1 -Dmingw32_HOST_OS=1 -Dx86_64_HOST_ARCH=1 -Icbits -IC:\Users\nutr1\AppData\Local\Programs\stack\x86_64-windows\msys2-20161025\mingw64\include -I.stack-work\dist\29cc6475\build\cbits -IC:\Users\nutr1\AppData\Local\Programs\stack\x86_64-windows\msys2-20161025\mingw64\include -I.stack-work\dist\29cc6475\build\autogen -I.stack-work\dist\29cc6475\build\global-autogen -include .stack-work\dist\29cc6475\build\autogen\cabal_macros.h -IC:\Users\nutr1\AppData\Local\Programs\stack\x86_64-windows\msys2-20161025\mingw64\include -IC:\Users\nutr1\AppData\Local\Programs\stack\x86_64-windows\ghc-8.8.2\lib\bytestring-0.10.10.0\include -IC:\Users\nutr1\AppData\Local\Programs\stack\x86_64-windows\ghc-8.8.2\lib\base-4.13.0.0\include -IC:\Users\nutr1\AppData\Local\Programs\stack\x86_64-windows\ghc-8.8.2\lib\integer-gmp-1.0.2.0\include -IC:\Users\nutr1\AppData\Local\Programs\stack\x86_64-windows\ghc-8.8.2\lib/include -IC:\Users\nutr1\AppData\Local\Programs\stack\x86_64-windows\ghc-8.8.2/lib/include/
2020-02-17 20:55:42.540009: [error]
Error:
--  While building package regex-posix-0.96.0.0 using:
      C:\sr\setup-exe-cache\x86_64-windows\Cabal-simple_Z6RU0evB_3.0.1.0_ghc-8.8.2.exe --builddir=.stack-work\dist\29cc6475 build --ghc-options " -fdiagnostics-color=always"
    Process exited with code: ExitFailure 1

Step to Reproduce

1. stack install regex-posix -v

Environment

• Windows 10 1909
• stack 2.1.3
• GHC 8.8.2
• regex-posix 0.96.0.0

[arbertrary]

I can confirm the reproducibility of this issue on Windows.
Issue does not occur on MacOS Catalina 10.15.3 (same stack, ghc and regex-posix version)

Most likely related to the removal of the internal regex implementation in this commit I guess. 5075a87

I tried e.g. these steps to manually get regex.h for my system from this stackoverflow question but wasn't successful: https://stackoverflow.com/questions/8230905/regex-h-for-windows

I'm not sure where on the system the GHC FFI is looking for the header files which are to be included.

[u2x1]

I'm not sure where on the system the GHC FFI is looking for the header files which are to be included.

The output of stack would tell us the directory where header files are included:

2020-02-17 20:55:42.489164: [warn] regex-posix > command was: C:\Users\nutr1\AppData\Local\Programs\stack\x86_64-windows\ghc-8.8.2\lib\../mingw/bin\gcc.exe -c .stack-work\dist\29cc6475\build\Text\Regex\Posix\Wrap_hsc_make.c -o .stack-work\dist\29cc6475\build\Text\Regex\Posix\Wrap_hsc_make.o -D__GLASGOW_HASKELL__=808 -Dmingw32_BUILD_OS=1 -Dx86_64_BUILD_ARCH=1 -Dmingw32_HOST_OS=1 -Dx86_64_HOST_ARCH=1 -Icbits -IC:\Users\nutr1\AppData\Local\Programs\stack\x86_64-windows\msys2-20161025\mingw64\include -I.stack-work\dist\29cc6475\build\cbits -IC:\Users\nutr1\AppData\Local\Programs\stack\x86_64-windows\msys2-20161025\mingw64\include -I.stack-work\dist\29cc6475\build\autogen -I.stack-work\dist\29cc6475\build\global-autogen -include .stack-work\dist\29cc6475\build\autogen\cabal_macros.h -IC:\Users\nutr1\AppData\Local\Programs\stack\x86_64-windows\msys2-20161025\mingw64\include -IC:\Users\nutr1\AppData\Local\Programs\stack\x86_64-windows\ghc-8.8.2\lib\bytestring-0.10.10.0\include -IC:\Users\nutr1\AppData\Local\Programs\stack\x86_64-windows\ghc-8.8.2\lib\base-4.13.0.0\include -IC:\Users\nutr1\AppData\Local\Programs\stack\x86_64-windows\ghc-8.8.2\lib\integer-gmp-1.0.2.0\include -IC:\Users\nutr1\AppData\Local\Programs\stack\x86_64-windows\ghc-8.8.2\lib/include -IC:\Users\nutr1\AppData\Local\Programs\stack\x86_64-windows\ghc-8.8.2/lib/include/

To me, it's C:\Users\nutr1\AppData\Local\Programs\stack\x86_64-windows\msys2-20161025\mingw64\include

I have also tried putting regex.h from regex-posix-clib into the path mentioned above. It did passed the GCC compile but when I tried to run GHCi the error turned to be undefined reference to 'regerror'.

[PaulJohnson]

I've got this too. There are two parts.

First, you need to have the libsystre package installed. This provides regex.h

pacman -S mingw-w64-x86_64-libsystre

Then you need to have gcc invoked with -IC:\msys64\mingw64\include on the command line (assuming you are compiling for 64-bit machines). That is probably going to require some incantation in the cabal file.

Oh, and there is probably going to have to be a similar link-time option too.

[PaulJohnson]

Not sure if this counts as a workaround or an actual solution, but here is what you need to do.

1. Install MinGW.

2. Within the MinGW shell install the libstre package. For 64-bit the incantation is pacman -S mingw-w64-x86_64-libsystre.

3. Add to your project stack.yaml file:
   extra-include-dirs:
- C:\msys64\mingw64\include

[PaulJohnson]

Correction to the above: you don't need mingw64. You just need to install with the _regex-posix-clib flag enabled (note the underscore).

With plain cabal: cabal install regex-posix -f _regex-posix-clib

In Stack, add the following to your stack.yaml:

extra-deps:
   - regex-posix-clib-2.7

flags:
   regex-posix:
      _regex-posix-clib: true

[cloudcrypt]

Correction to the above: you don't need mingw64. You just need to install with the _regex-posix-clib flag enabled (note the underscore).

With plain cabal: cabal install regex-posix -f _regex-posix-clib

In Stack, add the following to your stack.yaml:

extra-deps:
   - regex-posix-clib-2.7

flags:
   regex-posix:
      _regex-posix-clib: true

This solved it for me!
Will adding these to the stack.yaml cause any issues when building on Linux or MacOS?

[wolverian]

Can this behavior be made automatic, so that we can use the same stack.yaml on all platforms?

[pdcxs]

I add these codes to stack.yaml, it says:
Error while parsing $.flags.regex-posix - key "manual" not present

[tuomohopia]

I confirm @PaulJohnson's solution solves the problem on WIN10.

[pdcxs]

Sorry, I added the code into package.yaml but not the stack.yaml. Now it is solved. Thanks a lot.

[hasufell]

Can this behavior be made automatic, so that we can use the same stack.yaml on all platforms?

That is the correct fix. Please reopen this ticket @Nutr1t07