Fails on macOS Big Sur (?)

[MarcoPolo]

Hey there, I'm new to haskell.nix so it's possible I've done something wrong.

But following the directions (and some tweaking). Things don't seem to work on MacOS Big Sur. Likely becuase of the dylib issue and maybe because the cache doesn't contain everything I need?

When I use this for default.nix:

{
  # Fetch the latest haskell.nix and import its default.nix
  # Not using master so it's reproducible.
  haskellNix ? import (builtins.fetchTarball "https://github.com/input-output-hk/haskell.nix/archive/8970673cd07c1c62c13a35c7dba1fcc889487730.tar.gz") { }

  # haskell.nix provides access to the nixpkgs pins which are used by our CI,
  # hence you will be more likely to get cache hits when using these.
  # But you can also just use your own, e.g. '<nixpkgs>'.
, nixpkgsSrc ? haskellNix.sources.nixpkgs-2003

  # haskell.nix provides some arguments to be passed to nixpkgs, including some
  # patches and also the haskell.nix functionality itself as an overlay.
, nixpkgsArgs ? haskellNix.nixpkgsArgs

  # import nixpkgs with overlays
, pkgs ? import nixpkgsSrc nixpkgsArgs
}: pkgs.haskell-nix.project {
  # 'cleanGit' cleans a source directory based on the files known by git
  src = pkgs.haskell-nix.haskellLib.cleanGit {
    name = "haskell-nix-project";
    src = ./.;
  };
  # Specify the GHC version to use.
  compiler-nix-name = "ghc8102"; # Not required for `stack.yaml` based projects.
}

I get this error:

builder for '/nix/store/lszby9xx4lw69s4l5rq42bh0a98r31dw-popt-1.16.drv' failed with exit code 77

Because it failed to find a dylib.

When I do some tweaking (hoping to get a cache hit on the dylib) with this default.nix:

{
  # Fetch the latest haskell.nix and import its default.nix
  haskellNix ? import (builtins.fetchTarball "https://github.com/input-output-hk/haskell.nix/archive/c9dde4d9f4ad8eeaa117522563bdec0a4ff5a353.tar.gz") { }

  # haskell.nix provides access to the nixpkgs pins which are used by our CI,
  # hence you will be more likely to get cache hits when using these.
  # But you can also just use your own, e.g. '<nixpkgs>'.
  # , nixpkgsSrc ? haskellNix.sources.nixpkgs-2009
, nixpkgsSrc ? <nixpkgs>

  # haskell.nix provides some arguments to be passed to nixpkgs, including some
  # patches and also the haskell.nix functionality itself as an overlay.
, nixpkgsArgs ? haskellNix.nixpkgsArgs

  # import nixpkgs with overlays
, pkgs ? import nixpkgsSrc nixpkgsArgs
}: pkgs.haskell-nix.project {
  # 'cleanGit' cleans a source directory based on the files known by git
  src = pkgs.haskell-nix.haskellLib.cleanGit {
    name = "haskell-nix-project";
    src = ./.;
  };
  # Specify the GHC version to use.
  compiler-nix-name = "ghc8102"; # Not required for `stack.yaml` based projects.
}

I get a different, but similar error:

ld: file not found: /usr/lib/system/libcache.dylib for architecture x86_64
clang-7: error: linker command failed with exit code 1 (use -v to see invocation)
`cc' failed in phase `Linker'. (Exit code: 1)
error: --- Error --------------------------------------------------------------------------------------------------------------------------------------- nix-build
builder for '/nix/store/21vqa2x16mkgp5ffn29xywgp2wj7qqdd-nix-tools-exe-truncate-index-0.1.0.0.drv' failed with exit code 1
building '/nix/store/3ygjsfwgbgjaw1rwc2cwad7qzyfwizjq-hashable-lib-hashable-1.3.0.0.drv'...

I'm pretty sure I've setup the iohk hydra cache correctly since during the build I see a lot of:

copying path '/nix/store/...' from 'https://hydra.iohk.io'...

---

I guess my question is: Is this a known issue? If so I think it would be worth mentioning somewhere.

If not, is there an example default.nix that works on big sur?

Thanks! \o/

[rvl]

I'm not a macOS user, but I understand that the big sur problems are getting fixed in the nixpkgs-20.09 branch.

1. What happens if you replace <nixpkgs> with haskellNix.sources.nixpkgs-2009 ?

2. Also you may need to update your Haskell.nix rev to today's - 98ae014.

[MarcoPolo]

Thanks for the suggestion. That's one of the versions I tried. Specifically this default.nix:

{
  # Fetch the latest haskell.nix and import its default.nix
  haskellNix ? import (builtins.fetchTarball "https://github.com/input-output-hk/haskell.nix/archive/98ae014b5d35694a928e754bc9b381572a7e1adc.tar.gz") { }

  # haskell.nix provides access to the nixpkgs pins which are used by our CI,
  # hence you will be more likely to get cache hits when using these.
  # But you can also just use your own, e.g. '<nixpkgs>'.
  # , nixpkgsSrc ? haskellNix.sources.nixpkgs-2009
, nixpkgsSrc ? haskellNix.sources.nixpkgs-2009

  # haskell.nix provides some arguments to be passed to nixpkgs, including some
  # patches and also the haskell.nix functionality itself as an overlay.
, nixpkgsArgs ? haskellNix.nixpkgsArgs

  # import nixpkgs with overlays
, pkgs ? import nixpkgsSrc nixpkgsArgs
}: pkgs.haskell-nix.project {
  # 'cleanGit' cleans a source directory based on the files known by git
  src = pkgs.haskell-nix.haskellLib.cleanGit {
    name = "haskell-nix-project";
    src = ./.;
  };
  # Specify the GHC version to use.
  compiler-nix-name = "ghc8102"; # Not required for `stack.yaml` based projects.
}

leads to the error in popt:

configure: error: in `/private/tmp/nix-build-popt-1.16.drv-0/popt-1.16':
configure: error: C compiler cannot create executables
See `config.log' for more details.
error: --- Error --------------------------------------------------------------------------------------------------------------------------------------- nix-build
builder for '/nix/store/n1dlvf0ja6cmz0v9qaj15i3phb2fh208-popt-1.16.drv' failed with exit code 77
error: --- Error --------------------------------------------------------------------------------------------------------------------------------------- nix-build
1 dependencies of derivation '/nix/store/wnvjmxcq6bishbnvbc6k25jz1hkv4irk-rsync-3.1.3.drv' failed to build
error: --- Error --------------------------------------------------------------------------------------------------------------------------------------- nix-build
1 dependencies of derivation '/nix/store/2a3hw7y8dk9cdzdhx4pyypsvc87m44ls-haskell-nix-project-plan-to-nix-pkgs.drv' failed to build

And looking at the config.log, it's a dylib issue:

ld: file not found: /usr/lib/system/libcache.dylib for architecture x86_64

[rvl]

OK, too bad. That's as far as I can help.

[MarcoPolo]

Oh! so it turns out I need to specify the cache.nixos.org info if I override it. On macOS (or at least for me) these don't already exist.

So my nix.conf is actually:

trusted-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ= 
substituters = https://cache.nixos.org https://hydra.iohk.io

and that gets me post the post error since it can fetch it from cache.nixos.org.

But I think I finally get to compiling my own code and it fails with a similar issue:

$ nix-build -A hfp.components.exes.hfp-exe

...
Building library for hfp-0.1.0.0..
[1 of 2] Compiling Lib              ( src/Lib.hs, dist/build/Lib.o, dist/build/Lib.dyn_o )
[2 of 2] Compiling Paths_hfp        ( dist/build/autogen/Paths_hfp.hs, dist/build/Paths_hfp.o, dist/build/Paths_hfp.dyn_o )
ld: warning: /nix/store/c8j0gfzbkxblb9s64anmpxcsrq4hv5ih-libiconv-osx-10.12.6/lib/libiconv.dylib, ignoring unexpected dylib file
ld: file not found: /usr/lib/system/libcache.dylib for architecture x86_64
clang-7: error: linker command failed with exit code 1 (use -v to see invocation)
`cc' failed in phase `Linker'. (Exit code: 1)

[MarcoPolo]

fwiw I just tested on a linux box and it works fine.

[angerman]

Which nixpkgs is this, iirc BigSur needs master.

[MarcoPolo]

Good call, I thought the Big Sur fix was backported to 20.09, but that's not the case.

The 20.09 branch doesn't have the big sur fix. To get Big Sur working with the hydra cache the fix needs to be in 20.09 (or there needs to be a build with Nixpkgs-unstable). Thankfully the fix looks like it's currently being back ported to 20.09.

So my guess is this won't work with the cache until then. But I'll try building with Nixpkgs master and compiling ghc while I'm at it :)

[MarcoPolo]

I had to compile a lot of stuff, but it works if you use nixpkgs-unstable.

Should I leave this issue open until it works with the cache or close?

[rvl]

I'm greatly relieved that there is a fix in sight for this.
Let's keep this open until the backport PR NixOS/nixpkgs#105799 is merged and available in the nixpkgs-20.09-darwin channel.
Then we can bump the nixpkgs pin and build with iohk hydra.

[MarcoPolo]

Looks like it's possible that those changes won't be back ported.

[rvl]

Yes, looks like it's either 21.05 or unstable for the latest macOS.
We will probably need to add a new nixos-unstable pin in Haskell.nix until the next nixpkgs stable branch arrives.

[michaelpj]

We're giving up and switching to nixos-unstable for Plutus.

[Ptival]

I've been using staging-next myself.

[hamishmack]

I have added nixpkgs-unstable as a pin in #1025 (I think nixpkgs-unstable is some where between staging-next and nixos-unstable). Perhaps we can drop it once 21.0X comes out.

[michaelpj]

I don't think there's anything more to do here.