Error building on MacOS with M1 Pro about duckling

[j6e]

I have managed to build the code! As you said I had to download the x86_64 version of libpcre.

arch -x86_64 /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"
arch -x86_64 /usr/local/bin/brew install pcre
stack build

Thanks!

[stroxler]

It's a bit unfortunate that stack can't repeat the failed section at the bottom, it's hard to find.

The relevant lines are right near the top:

regex-pcre        > Cabal-simple_SvXsv1f__3.0.1.0_ghc-8.8.4: The program 'pkg-config' version
regex-pcre        > >=0.9.0 is required but it could not be found.

The regex-pcre library needs you to have a system dependency (i.e. a C library not managed by stack).

You could get it from whatever package manager you use on your macos system, e.g. homebrew:
https://formulae.brew.sh/formula/pkg-config

[j6e]

thanks, it worked but now I get a different error:

Building all executables for `duckling' once. After a successful build of all of them, only specified executables will be rebuilt.
duckling> build (lib + exe)
Preprocessing library for duckling-0.2.0.0..
Building library for duckling-0.2.0.0..
ld: warning: -undefined dynamic_lookup may not work with chained fixups
ld: warning: ignoring file /opt/homebrew/Cellar/pcre/8.45/lib/libpcre.dylib, building for macOS-x86_64 but attempting to link with file built for macOS-arm64
Preprocessing executable 'duckling-expensive' for duckling-0.2.0.0..
Building executable 'duckling-expensive' for duckling-0.2.0.0..
Linking .stack-work/dist/x86_64-osx/Cabal-3.0.1.0/build/duckling-expensive/duckling-expensive ...
ld: warning: ignoring file /opt/homebrew/Cellar/pcre/8.45/lib/libpcre.dylib, building for macOS-x86_64 but attempting to link with file built for macOS-arm64
Undefined symbols for architecture x86_64:
  "_pcre_compile", referenced from:
      _LcclY_info in libHSregex-pcre-0.95.0.0-2ET47luPseYCyxUKIqxikm.a(Wrap.o)
  "_pcre_exec", referenced from:
      _LccBZ_info in libHSregex-pcre-0.95.0.0-2ET47luPseYCyxUKIqxikm.a(Wrap.o)
      _LccO3_info in libHSregex-pcre-0.95.0.0-2ET47luPseYCyxUKIqxikm.a(Wrap.o)
      _LccQr_info in libHSregex-pcre-0.95.0.0-2ET47luPseYCyxUKIqxikm.a(Wrap.o)
      _LccRN_info in libHSregex-pcre-0.95.0.0-2ET47luPseYCyxUKIqxikm.a(Wrap.o)
  "_pcre_fullinfo", referenced from:
      _LccA5_info in libHSregex-pcre-0.95.0.0-2ET47luPseYCyxUKIqxikm.a(Wrap.o)
      _LccLg_info in libHSregex-pcre-0.95.0.0-2ET47luPseYCyxUKIqxikm.a(Wrap.o)
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
`gcc' failed in phase `Linker'. (Exit code: 1)

Error: [S-7282]
       Stack failed to execute the build plan.

       While executing the build plan, Stack encountered the following errors:

       [S-7011]
       While building package duckling-0.2.0.0 (scroll up to its section to see the error) using:
       /Users/user/.stack/setup-exe-cache/x86_64-osx/Cabal-simple_SvXsv1f__3.0.1.0_ghc-8.8.4 --verbose=1 --builddir=.stack-work/dist/x86_64-osx/Cabal-3.0.1.0 build lib:duckling exe:custom-dimension-example exe:duckling-example-exe exe:duckling-expensive exe:duckling-regen-exe exe:duckling-request-sample --ghc-options " -fdiagnostics-color=always"
       Process exited with code: ExitFailure 1

[stroxler]

Hmm. I know what's happening here, but I'm unsure how to fix it:

• It looks like brew installed an arm64 binary for libpcre, which makes sense on an M1
• But stack is trying to build Haskell as x86_64. That also sort of makes sense, because an M1 can run intel binaries through an emulation layer. But we can't mix-and-match - the linker is unable to

The solutions are to either:

• Get stack to build arm64. I'm unsure how to do that
• Or, download an x86_64 libpcre and put it on the linker path

I might be able to work this out, but I'm not much of an expert on this layer of the stack so cc @chessai who might know the solution straightaway