ghc962: could not execute: otool

[avdv]

Describe the bug

I am trying to use GHC 9.6.2 from nixpkgs with Bazel but receive this error:

ERROR: /Users/claudio/rules_haskell/tools/runfiles/BUILD.bazel:24:16: HaskellLinkDynamicLibrary tools/runfiles/libHStoolsZSrunfilesZSrunfiles-ghc9.6.2.dylib failed: (Exit 1): process-wrapper failed: error executing command 
  (cd /private/var/tmp/_bazel_claudio/afceb7d1cdeddc94d64e34c0a088ac89/sandbox/processwrapper-sandbox/455/execroot/rules_haskell && \
  exec env - \
    CC_WRAPPER_CC_PATH=external/nixpkgs_config_cc/cc_wrapper.sh \
    CC_WRAPPER_CPU=darwin_arm64 \
    CC_WRAPPER_PLATFORM=darwin \
    LANG=C.UTF-8 \
    MUST_EXTRACT_ABI=false \
    PATH=/nix/store/ccjpkiqx40y6y98rpa2l8z4xg9mdlmq7-posix-toolchain/bin \
    RULES_HASKELL_DOCDIR_PATH=/nix/store/ywfzw2q59fna075p6ww98zlls4pgw17c-ghc-9.6.2/lib/ghc-9.6.2/lib/../../../../ya2qgcdazcvdb478zlzz97xpwp79jfjv-ghc-9.6.2-doc/share/doc/ghc/html/libraries/base-4.18.0.0 \
    RULES_HASKELL_GHC_PATH=external/rules_haskell_ghc_nixpkgs/bin/ghc \
    RULES_HASKELL_GHC_PKG_PATH=external/rules_haskell_ghc_nixpkgs/bin/ghc-pkg \
    RULES_HASKELL_LIBDIR_PATH=/nix/store/ywfzw2q59fna075p6ww98zlls4pgw17c-ghc-9.6.2/lib/ghc-9.6.2/lib \
    TMPDIR=/tmp \
  /var/tmp/_bazel_claudio/install/aa60e81d6fcd23c7034d0325a85596ce/process-wrapper '--timeout=0' '--kill_delay=15' '--stats=/private/var/tmp/_bazel_claudio/afceb7d1cdeddc94d64e34c0a088ac89/sandbox/processwrapper-sandbox/455/stats.out' bazel-out/darwin_arm64-opt-exec-C7777A24/bin/haskell/ghc_wrapper bazel-out/darwin_arm64-fastbuild/bin/tools/runfiles/compile_flags_runfiles____HaskellLinkDynamicLibrary bazel-out/darwin_arm64-fastbuild/bin/tools/runfiles/extra_args_runfiles____HaskellLinkDynamicLibrary)
/Library/Developer/CommandLineTools/usr/bin/install_name_tool: warning: changes being made to the file will invalidate the code signature in: bazel-out/darwin_arm64-fastbuild/bin/tools/runfiles/libHStoolsZSrunfilesZSrunfiles-ghc9.6.2.dylib
bazel-out/darwin_arm64-fastbuild/bin/tools/runfiles/libHStoolsZSrunfilesZSrunfiles-ghc9.6.2.dylib.resign: replacing existing signature
ghc-9.6.2: could not execute: otool

Note that PATH is set to /nix/store/ccjpkiqx40y6y98rpa2l8z4xg9mdlmq7-posix-toolchain/bin inside Bazel's sandbox.

However, using GHC 9.4.6 or 9.2.8 works just fine.

Looking at GHC's settings ( /nix/store/ywfzw2q59fna075p6ww98zlls4pgw17c-ghc-9.6.2/lib/ghc-9.6.2/lib/settings) I notice that the otool command is just set to otool:

,("otool command", "otool")

But previously, for former GHC versions it is properly set (e.g. /nix/store/lyfm7yz87ygvp8lkizxn43jcc11irpyq-ghc-9.4.6/lib/ghc-9.4.6/settings):

,("otool command", "/nix/store/s9j9nksvxalyw464x6q1brdp79ga1qhr-cctools-binutils-darwin-973.0.1/bin/otool")

Steps To Reproduce

(it is a bit more involved to create a few simple steps to reproduce and I think it is quite clear what the problem is. I can provide these steps if wanted)

Expected behavior

GHC should be able to execute otool even it is not on the PATH.

Additional context

Add any other context about the problem here.

Notify maintainers

Metadata

Please run nix-shell -p nix-info --run "nix-info -m" and paste the result.

[user@system:~]$ nix-shell -p nix-info --run "nix-info -m" - system: `"aarch64-darwin"`
 - host os: `Darwin 21.6.0, macOS 12.7`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.13.3`
 - nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixpkgs`

[cdepillabout]

@avdv Thanks for reporting this.

I'm not sure any of the Haskell maintainers are that knowledgeable about aarch64-darwin. You may not get any help with this unless you're willing to investigate yourself.

My guess is that this at least has something to do with the differences between the GHC expressions for 9.4 and 9.6, where 9.6 is based on Hadrian:

• https://github.com/NixOS/nixpkgs/blob/ff562fa5fc91523e2222ee5dc4600162a775eddb/pkgs/development/compilers/ghc/9.4.7.nix

vs

• https://github.com/NixOS/nixpkgs/blob/ff562fa5fc91523e2222ee5dc4600162a775eddb/pkgs/development/compilers/ghc/9.6.3.nix

[avdv]

Thank you for the pointer, @cdepillabout. I could pinpoint the problem (which also manifests itself on x86_64-darwin BTW).

The hadrian build creates a bindist, which has to be configured again. Running make install generates the final settings file. The configure script of the bindist, however, does not care about the OTOOL env variable, but uses the OtoolCmd env variable instead... Same for INSTALL_NAME_TOOL vs. InstallNameToolCmd.

\edit: created an upstream issue here => https://gitlab.haskell.org/ghc/ghc/-/issues/24211