elm-format fails to install alongside elm (darwin)

[robx]

Issue description

Not sure whether this is darwin-specific. I cannot install elm next to elm-format, because both want link /libHStransformers-compat-0.6.2-DR0vsQLKu2k3Tes0C8KQG1-ghc8.2.2.dylib.

It seems wrong for either of the packages to link shared libraries. I suspect this is because e.g. elm-format.nix sets isLibrary: true. I'd be happy to submit a patch to change this, but there seems to be a stack of scripts that's meant to generate this that's too deep for me.

Steps to reproduce

nix-env -iA nixpkgs.elmPackages.elm
nix-env -iA nixpkgs.elmPackages.elm-format

Technical details

• system: "x86_64-darwin"
• host os: Darwin 18.2.0, macOS 10.14.2
• multi-user?: no
• sandbox: no
• version: nix-env (Nix) 2.1.3
• channels(rob): "nixpkgs-19.03pre161900.61c3169a0e1"
• nixpkgs: /Users/rob/.nix-defexpr/channels/nixpkgs

[matthewbauer]

Usually we need a justStaticExecutables for these to work currently. Not sure if that is currently possible? You can also set meta.priority to a different number for each (default is 5).

/cc @domenkozar @jerith666

[jerith666]

I think this must be darwin-specific; I have these packages happily coexisting alongside each other in environment.systemPackages on NixOS:

$ ls -l /run/current-system/sw/bin/elm*
lrwxrwxrwx 6 root root 62 Dec 31  1969 /run/current-system/sw/bin/elm -> /nix/store/cnl19cwicwlgnzf4fsprvs6z3rlfizmj-elm-0.19.0/bin/elm
lrwxrwxrwx 6 root root 75 Dec 31  1969 /run/current-system/sw/bin/elm-format -> /nix/store/v5dgvj1zms6h4yssg55mh3cvhlrwxpcd-elm-format-0.8.1/bin/elm-format

[robx]

Yes, looks darwin-specific, via

nixpkgs/pkgs/development/haskell-modules/generic-builder.nix

Line 299 in 3504cfe

# Work around a limit in the macOS Sierra linker on the number of paths

[domenkozar]

Fixed in #53326