ghc.bash is not a Mach-O file

[philderbeast]

Following the instructions in the readme to use ghc-artefact-nix bare to get ghc/master fails on x86_64-darwin with ghc.bash is not a Mach-O file:

> git clone https://github.com/mpickering/ghc-artefact-nix.git
Cloning into 'ghc-artefact-nix'...
remote: Enumerating objects: 119, done.
remote: Counting objects: 100% (28/28), done.
remote: Compressing objects: 100% (21/21), done.
remote: Total 119 (delta 13), reused 15 (delta 7), pack-reused 91
Receiving objects: 100% (119/119), 26.16 KiB | 1.74 MiB/s, done.
Resolving deltas: 100% (61/61), done.
> cd ghc-artefact-nix/
> ./ghc-head-from.sh
Fetching artefact from ghc/master
error: builder for '/nix/store/hz4rmdlaxwdbqvq7c4bb3plms461bb3j-ghc-9.5.20220716.drv' failed with exit code 1;
       last 4 log lines:
       > unpacking sources
       > unpacking source archive /nix/store/aphdkqdml3q05adg0g671jfjsm518rhy-ghc-x86_64-darwin-validate.tar.xz?job=x86_64-darwin-validate
       > source root is ghc-9.5.20220716-x86_64-apple-darwin
       > error: install_name_tool: input file: ./ghc-9.5.20220716-x86_64-apple-darwin/completion/ghc.bash is not a Mach-O file
       For full logs, run 'nix log /nix/store/hz4rmdlaxwdbqvq7c4bb3plms461bb3j-ghc-9.5.20220716.drv'.
> nix --version
nix (Nix) 2.4
> nix log /nix/store/hz4rmdlaxwdbqvq7c4bb3plms461bb3j-ghc-9.5.20220716.drv
@nix { "action": "setPhase", "phase": "unpackPhase" }
unpacking sources
unpacking source archive /nix/store/aphdkqdml3q05adg0g671jfjsm518rhy-ghc-x86_64-darwin-validate.tar.xz?job=x86_64-darwin-validate
source root is ghc-9.5.20220716-x86_64-apple-darwin
error: install_name_tool: input file: ./ghc-9.5.20220716-x86_64-apple-darwin/completion/ghc.bash is not a Mach-O file
> sw_vers
ProductName:    macOS
ProductVersion: 11.6.7
BuildVersion:   20G630