haskellPackages: Add buildFromCabalSdist (faster, tested)

pkgs/development/haskell-modules/lib/compose.nix

···
      directly. The effect is that the package is built as if it were published
      on hackage. This can be used as a test for the source distribution,
      assuming the build fails when packaging mistakes are in the cabal file.
+
+     A faster implementation using `cabal-install` is available as
+     `buildFromCabalSdist` in your Haskell package set.
    */
   buildFromSdist = pkg: overrideCabal (drv: {
     src = "${sdistTarball pkg}/${pkg.pname}-${pkg.version}.tar.gz";

pkgs/development/haskell-modules/make-package-set.nix

···
       withHoogle = self.ghcWithHoogle;
     };
 
+    /*
+      Run `cabal sdist` on a source.
+
+      Unlike `haskell.lib.sdistTarball`, this does not require any dependencies
+      to be present, as it uses `cabal-install` instead of building `Setup.hs`.
+      This makes `cabalSdist` faster than `sdistTarball`.
+    */
+    cabalSdist = {
+      src,
+      name ? if src?name then "${src.name}-sdist.tar.gz" else "source.tar.gz"
+    }:
+      pkgs.runCommandNoCCLocal name
+        {
+          inherit src;
+          nativeBuildInputs = [ buildHaskellPackages.cabal-install ];
+          dontUnpack = false;
+        } ''
+        unpackPhase
+        cd "''${sourceRoot:-.}"
+        patchPhase
+        mkdir out
+        HOME=$PWD cabal sdist --output-directory out
+        mv out/*.tar.gz $out
+      '';
+
+    /*
+      Like `haskell.lib.buildFromSdist`, but using `cabal sdist` instead of
+      building `./Setup`.
+
+      Unlike `haskell.lib.buildFromSdist`, this does not require any dependencies
+      to be present. This makes `buildFromCabalSdist` faster than `haskell.lib.buildFromSdist`.
+    */
+    buildFromCabalSdist = pkg:
+      haskellLib.overrideSrc
+        {
+          src = self.cabalSdist { inherit (pkg) src; };
+          version = pkg.version;
+        }
+        pkg;
+
   }

pkgs/test/haskell/cabalSdist/default.nix

···
+{ lib, haskellPackages, runCommand }:
+
+let
+  localRaw = haskellPackages.callCabal2nix "local" ./local {};
+in
+lib.recurseIntoAttrs rec {
+
+  helloFromCabalSdist = haskellPackages.buildFromCabalSdist haskellPackages.hello;
+
+  # A more complicated example with a cabal hook.
+  hercules-ci-cnix-store = haskellPackages.buildFromCabalSdist haskellPackages.hercules-ci-cnix-store;
+
+  localFromCabalSdist = haskellPackages.buildFromCabalSdist localRaw;
+
+  assumptionLocalHasDirectReference = runCommand "localHasDirectReference" {
+    drvPath = builtins.unsafeDiscardOutputDependency localRaw.drvPath;
+  } ''
+    grep ${./local} $drvPath >/dev/null
+    touch $out
+  '';
+
+  localHasNoDirectReference = runCommand "localHasNoDirectReference" {
+    drvPath = builtins.unsafeDiscardOutputDependency localFromCabalSdist.drvPath;
+  } ''
+    grep -v ${./local} $drvPath >/dev/null
+    touch $out
+  '';
+}

pkgs/test/haskell/cabalSdist/local/CHANGELOG.md

···
+# Revision history for local
+
+## 0.1.0.0 -- YYYY-mm-dd
+
+* First version. Released on an unsuspecting world.

pkgs/test/haskell/cabalSdist/local/app/Main.hs

···
+module Main where
+
+main :: IO ()
+main = putStrLn "Hello, Haskell!"

pkgs/test/haskell/cabalSdist/local/local.cabal

···
+cabal-version:      2.4
+name:               local
+version:            0.1.0.0
+
+synopsis: Nixpkgs test case
+license:  MIT
+extra-source-files: CHANGELOG.md
+
+executable local
+    main-is:          Main.hs
+    build-depends:    base
+    hs-source-dirs:   app
+    default-language: Haskell2010

pkgs/test/haskell/default.nix

···
 
 lib.recurseIntoAttrs {
   shellFor = callPackage ./shellFor { };
+  cabalSdist = callPackage ./cabalSdist { };
   documentationTarball = callPackage ./documentationTarball { };
   setBuildTarget = callPackage ./setBuildTarget { };
   writers = callPackage ./writers { };