Error building package regex-posix-0.96.0.0 with Stack - haskell

Question

I'm trying to compile a new Haskell project with Stack, but I'm getting this error message:
$ stack build
WARNING: Ignoring regex-posix's bounds on base (<0 && >=4.3 && <4.16); using base-4.14.1.0.
Reason: trusting snapshot over cabal file dependency information.
regex-posix > configure
regex-posix > Configuring regex-posix-0.96.0.0...
regex-posix > build
regex-posix > Preprocessing library for regex-posix-0.96.0.0..
regex-posix > compiling .stack-work\dist\274b403a\build\Text\Regex\Posix\Wrap_hsc_make.c failed (exit code 1)
regex-posix > rsp file was: ".stack-work\\dist\\274b403a\\build\\Text\\Regex\\Posix\\hsc5BFC.rsp"
regex-posix > command was: C:\Users\mark\AppData\Local\Programs\stack\x86_64-windows\ghc-8.10.4\lib\../mingw/bin\gcc.exe -c .stack-work\dist\274b403a\build\Text\Regex\Posix\Wrap_hsc_make.c -o .stack-work\dist\274b403a\build\Text\Regex\Posix\Wrap_hsc_make.o -D__GLASGOW_HASKELL__=810 -Dmingw32_BUILD_OS=1 -Dx86_64_BUILD_ARCH=1 -Dmingw32_HOST_OS=1 -Dx86_64_HOST_ARCH=1 -Icbits -IC:\Users\mark\AppData\Local\Programs\stack\x86_64-windows\msys2-20180531\mingw64\include -I.stack-work\dist\274b403a\build\cbits -IC:\Users\mark\AppData\Local\Programs\stack\x86_64-windows\msys2-20180531\mingw64\include -I.stack-work\dist\274b403a\build\autogen -I.stack-work\dist\274b403a\build\global-autogen -include .stack-work\dist\274b403a\build\autogen\cabal_macros.h -IC:\Users\mark\AppData\Local\Programs\stack\x86_64-windows\msys2-20180531\mingw64\include -IC:\Users\mark\AppData\Local\Programs\stack\x86_64-windows\ghc-8.10.4\lib\bytestring-0.10.12.0\include -IC:\Users\mark\AppData\Local\Programs\stack\x86_64-windows\ghc-8.10.4\lib\base-4.14.1.0\include -IC:\Users\mark\AppData\Local\Programs\stack\x86_64-windows\ghc-8.10.4\lib\integer-gmp-1.0.3.0\include -IC:\Users\mark\AppData\Local\Programs\stack\x86_64-windows\ghc-8.10.4\lib/include -IC:\Users\mark\AppData\Local\Programs\stack\x86_64-windows\ghc-8.10.4/lib/include/
regex-posix > error: Wrap.hsc:96:10: fatal error: regex.h: No such file or directory
regex-posix > compilation terminated.
regex-posix >
Progress 1/2
-- While building package regex-posix-0.96.0.0 (scroll up to its section to see the error) using:
C:\sr\setup-exe-cache\x86_64-windows\Cabal-simple_Z6RU0evB_3.2.1.0_ghc-8.10.4.exe --builddir=.stack-work\dist\274b403a build --ghc-options " -fdiagnostics-color=always"
Process exited with code: ExitFailure 1
I don't understand the initial warning. When looking at the regex-posix package's dependencies, it does list base (>=4.3 && <4.16) as a dependency, but where does the <0 come from?
I've set the resolver to LTS 18.0 in stack.yaml:
resolver: lts-18.0
According to the documentation of LTS 18.0, it uses base-4.14.1.0. If the versioning is lexicographic, I'd think that 4.14.1.0 fits the range that regex-posix requires (if we, for a moment, ignore the strange <0 constraint).
Here are the relevant parts of my package.yaml:
dependencies:
- base >= 4.7 && < 5
- regex-posix >= 0.96
library:
source-dirs: src
ghc-options:
- -Wall
My stack version:
$ stack --version
Version 2.7.1, Git revision 8afe0c2932716b0441cf4440d6942c59568b6b19 x86_64 hpack-0.34.4
I'm on Windows 10.
FWIW, it's not that I care much about regex-posix in itself. In reality, I'm trying to set up a test project, and test-framework depends on regex-posix.
How can I resolve this issue so that I can compile my code?

Answer 1

The error is not about the version, that is just a warning. The real error is about a missing "regex.h" header for the underlying C library. That header is almost always present on posix platforms (like linux), but not on Windows. See https://github.com/haskell-hvr/regex-posix/issues/4
Particularly this comment by Paul Johnson:
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
In that thread there is also a comment about the <0 version: https://github.com/haskell-hvr/regex-posix/issues/4#issuecomment-699786233