nixpkgs/pkgs/development/haskell-modules/default.nix
Peter Simons 3c8b33eee4 haskell-modules: implement overrideScope method for deep overriding
deepOverride turns out to be completely unfeasible for non-trivial overrides.
Nix evaluates for an eternity, and then comes back saying:

  Too many heap sections: Increase MAXHINCR or MAX_HEAP_SECTS
  nix-instantiate killed by signal 6

The hand-written deep-override, on the other hand, performs the job in a
fraction of a second, no problem.

All bow to Russell O'Connor!
2015-01-08 18:50:19 +01:00

56 lines
1.8 KiB
Nix

{ pkgs, stdenv, ghc
, packageSetConfig ? (self: super: {})
, overrides ? (self: super: {})
, provideOldAttributeNames ? false
}:
with ./lib.nix;
let
fix = f: let x = f x // { __unfix__ = f; }; in x;
extend = rattrs: f: self: let super = rattrs self; in super // f self super;
haskellPackages = self:
let
mkDerivation = pkgs.callPackage ./generic-builder.nix {
inherit stdenv ghc;
inherit (pkgs) fetchurl pkgconfig glibcLocales coreutils gnugrep gnused;
inherit (self) jailbreak-cabal;
hscolour = overrideCabal self.hscolour (drv: {
isLibrary = false;
noHaddock = true;
hyperlinkSource = false; # Avoid depending on hscolour for this build.
postFixup = "rm -rf $out/lib $out/share $out/nix-support";
});
};
overrideCabal = drv: f: drv.override (args: args // {
mkDerivation = drv: args.mkDerivation (drv // f drv);
});
callPackageWithScope = scope: drv: args: (stdenv.lib.callPackageWith scope drv args) // {
overrideScope = f: callPackageWithScope (fix (extend scope.__unfix__ f)) drv args;
};
defaultScope = pkgs // pkgs.xlibs // pkgs.gnome // self;
callPackage = drv: args: callPackageWithScope defaultScope drv args;
in
import ./hackage-packages.nix { inherit pkgs stdenv callPackage; } self // {
inherit ghc mkDerivation callPackage;
ghcWithPackages = pkgs: callPackage ./with-packages-wrapper.nix { packages = pkgs self; };
};
compatLayer = if provideOldAttributeNames then import ./compat-layer.nix else (self: super: {});
commonConfiguration = import ./configuration-common.nix { inherit pkgs; };
in
fix (extend (extend (extend (extend haskellPackages commonConfiguration) packageSetConfig) overrides) compatLayer)