settings.<package>.custom is ignored when package.<package>.source is a git repository

[Thrithralas]

Problem

When specifying source as per the documentation, settings.<package>.custom is seemingly not applied.

Detailed Description

I'm not sure if this is actually a bug, I'm probably doing something wrong. Specifically, I'm trying to make a project with llvm-hs as its dependency, but I'm trying to use the llvm-15 branch from the git repository, as the hackage package is extremely outdated. My solution to adding in the llvm dependency looked like the following in when using the hackage version (some settings omitted for clarity, but I can post the whole file if need be):

{
  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
    flake-parts.url = "github:hercules-ci/flake-parts";
    haskell-flake.url = "github:srid/haskell-flake";
    ...
  };
  outputs = inputs@{ self, nixpkgs, flake-parts, ... }:
    flake-parts.lib.mkFlake { inherit inputs; } {
      systems = nixpkgs.lib.systems.flakeExposed;
      .
      .
      .
      perSystem = { self', pkgs, config, ... }:
        {
          haskellProjects.default = {
            settings.llvm-hs = {
              broken = false;
              jailbreak = true;
              custom = pkgs.haskell.lib.compose.overrideCabal (drv: {
                libraryToolDepends = (drv.libraryToolDepends or []) ++ [ pkgs.llvmPackages_9.llvm.dev ];
              });
            };
           .
           .
           .
          };
       };
    };
}

This works fine and it finds llvm-config (it runs into another unrelated error after it, but that's irrelevant)

The same however does not work, the moment I switch I specify source to be the git repository:

{
  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
    flake-parts.url = "github:hercules-ci/flake-parts";
    haskell-flake.url = "github:srid/haskell-flake";
    llvm-hs = {
      url = "github:llvm-hs/llvm-hs/llvm-15";
      flake = false;
    };
    ...
  };
  outputs = inputs@{ self, nixpkgs, flake-parts, ... }:
    flake-parts.lib.mkFlake { inherit inputs; } {
      systems = nixpkgs.lib.systems.flakeExposed;
      .
      .
      .
      perSystem = { self', pkgs, config, ... }:
        {
          haskellProjects.default = {
            packages.llvm-hs.source = inputs.llvm-hs + "/llvm-hs"; # the project is not in the root directory
            settings.llvm-hs = {
              broken = false;
              jailbreak = true;
              custom = pkgs.haskell.lib.compose.overrideCabal (drv: {
                libraryToolDepends = (drv.libraryToolDepends or []) ++ [ pkgs.llvmPackages_15.llvm.dev ];
              });
            };
           .
           .
           .
          };
       };
    };
}

The build now fails, due it not being able to find llvm-config on the path. The package does supply the llvm-config program, as entering a nix shell with the program installed and just building the llvm-hs package with cabal is working fine. Same issue with the llvm-12 branch. The llvm-9 branch has a different error, where llvm-config is explicitly written into the cabal file as an external dependency and it fails due to an unsupplied module parameter.

I'll add a minimal reproducible example in a few hours, once I get home.

The error, just in case it's necessary:

error: builder for '/nix/store/fvw0fsqpv5ikg6d6frjgphhwsgs6pxaw-llvm-hs-source-15.0.0.drv' failed with exit code 1;
       last 10 log lines:
       > [2 of 2] Linking Setup
       > Running phase: updateAutotoolsGnuConfigScriptsPhase
       > Running phase: configurePhase
       > configureFlags: --verbose --prefix=/nix/store/vnc6pvs123g7ihcgxbhn2rw1mhbksbz9-llvm-hs-source-15.0.0 --libdir=$prefix/lib/$compiler --libsubdir=$abi/$libname --docdir=/share/doc/llvm-hs-15.0.0 --with-gcc=gcc --package-db=/build/tmp.twmXnmS6dC/package.conf.d --ghc-options=-j16 +RTS -A64M -RTS --disable-split-objs --enable-library-profiling --profiling-detail=exported-functions --disable-profiling --enable-shared --disable-coverage --enable-static --disable-executable-dynamic --enable-tests --disable-benchmarks --enable-library-vanilla --disable-library-for-ghci --ghc-option=-split-sections --ghc-options=-haddock --extra-lib-dirs=/nix/store/wyw0d6r22mzl4g7wk1rkif9fsks00qbv-ncurses-6.4/lib --extra-lib-dirs=/nix/store/zabxhfpsgkb9c4sb7fy50pn1l1kczzv2-libffi-3.4.4/lib --extra-lib-dirs=/nix/store/wanbfij8izz6kjxrqj21gh2fdcb93wg7-gmp-with-cxx-6.3.0/lib
       > Using Parsec parser
       > CallStack (from HasCallStack):
       >   withMetadata, called at libraries/Cabal/Cabal/src/Distribution/Simple/Utils.hs:370:14 in Cabal-3.8.1.0:Distribution.Simple.Utils
       > Error: Setup: The program 'llvm-config' version >=15.0 && <15.1 is required
       > but it could not be found.
       >
       For full logs, run 'nix log /nix/store/fvw0fsqpv5ikg6d6frjgphhwsgs6pxaw-llvm-hs-source-15.0.0.drv'.

[srid]

The settings overlay is applied on top of the packages overlay:

haskell-flake/nix/modules/project/outputs.nix

Lines 86 to 89 in 1e29717

	finalOverlay = lib.composeManyExtensions [
	config.packagesOverlay
	config.settingsOverlay
	];

So I don't see how one could impact the other.

Are you able to reproduce this with some other simple package (not llvm-hs). Because, maybe the git repo is at fault here for not respecting libraryToolDepends?

But yes, if you have a minimal repro, please file a bug report. I've made this one a Discussion since we don't know for sure yet whether this is a bug in haskell-flake.

[Thrithralas]

I've made a minimum reproducible example, see here: https://github.com/Thrithralas/haskell-flake-237-reproducible

• The llvm directory contains a reproducible setup for llvm-hs specifically. Uncommenting the source declaration and the and changing the llvm version to 15 produces the issue as shown in its README. Without the source, it builds fine, but crashes later on (though in the error, the succesfull use of llvm-config can be seen).
• The sample-project is a project which uses the hello program in the same manner as llvm-hs uses llvm-configure in its Setup phase.
• using-sample-project simply uses the project above, failing to find hello during the Setup phase.

I'll try to add a reproducibe build for an existing package once I get home. I'm not that familiar with the haskell/nix infrastructure, but libraryToolDepends seems to be for packages which are required during the Setup phase.

[johnhampton]

I ran into this problem as well. I was planning on filing a bug report today. It appears that none of the settings i.e. check and jailbreak are applied when the source is a specified. It broke fairly recently, commit c301f31 works fine but master doesn't work.

https://github.com/johnhampton/haskell-flake-bug-repo demonstrates the problem.

[srid]

Thanks, let me try to reproduce this. John's repo is taking a while to build.

dd0d3b9 is the only commit I see to be significant recent change.

[srid]

Confirmed: #238