From 46bb6a78dbcf293dc651b8bcb02f16e6d78b24ae Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Sat, 26 Feb 2022 13:28:12 +0100
Subject: [PATCH 1/2] haskellPackages.callCabal2nix: Use stdenvNoCC

Delays C compiler realisation to the actual build, which is more
parallelizable; doesn't block the evaluator.
---
 pkgs/development/haskell-modules/make-package-set.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkgs/development/haskell-modules/make-package-set.nix b/pkgs/development/haskell-modules/make-package-set.nix
index e9ce4f127051..705a5b3e96f0 100644
--- a/pkgs/development/haskell-modules/make-package-set.nix
+++ b/pkgs/development/haskell-modules/make-package-set.nix
@@ -124,7 +124,7 @@ let
   haskellSrc2nix = { name, src, sha256 ? null, extraCabal2nixOptions ? "" }:
     let
       sha256Arg = if sha256 == null then "--sha256=" else ''--sha256="${sha256}"'';
-    in buildPackages.stdenv.mkDerivation {
+    in buildPackages.stdenvNoCC.mkDerivation {
       name = "cabal2nix-${name}";
       nativeBuildInputs = [ buildPackages.cabal2nix-unwrapped ];
       preferLocalBuild = true;

From b4524d8eda7fae5fc81e83286a402a37526220eb Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Sat, 26 Feb 2022 13:38:11 +0100
Subject: [PATCH 2/2] haskellPackages.haskellSrc2nix: stdenvNoCC.mkDerivation
 -> runCommand

No need to fuss with phases.
---
 .../haskell-modules/make-package-set.nix          | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/pkgs/development/haskell-modules/make-package-set.nix b/pkgs/development/haskell-modules/make-package-set.nix
index 705a5b3e96f0..86f29e731133 100644
--- a/pkgs/development/haskell-modules/make-package-set.nix
+++ b/pkgs/development/haskell-modules/make-package-set.nix
@@ -124,20 +124,17 @@ let
   haskellSrc2nix = { name, src, sha256 ? null, extraCabal2nixOptions ? "" }:
     let
       sha256Arg = if sha256 == null then "--sha256=" else ''--sha256="${sha256}"'';
-    in buildPackages.stdenvNoCC.mkDerivation {
-      name = "cabal2nix-${name}";
+    in buildPackages.runCommand "cabal2nix-${name}" {
       nativeBuildInputs = [ buildPackages.cabal2nix-unwrapped ];
       preferLocalBuild = true;
       allowSubstitutes = false;
-      phases = ["installPhase"];
       LANG = "en_US.UTF-8";
       LOCALE_ARCHIVE = pkgs.lib.optionalString (buildPlatform.libc == "glibc") "${buildPackages.glibcLocales}/lib/locale/locale-archive";
-      installPhase = ''
-        export HOME="$TMP"
-        mkdir -p "$out"
-        cabal2nix --compiler=${self.ghc.haskellCompilerName} --system=${hostPlatform.config} ${sha256Arg} "${src}" ${extraCabal2nixOptions} > "$out/default.nix"
-      '';
-  };
+    } ''
+      export HOME="$TMP"
+      mkdir -p "$out"
+      cabal2nix --compiler=${self.ghc.haskellCompilerName} --system=${hostPlatform.config} ${sha256Arg} "${src}" ${extraCabal2nixOptions} > "$out/default.nix"
+    '';
 
   all-cabal-hashes-component = name: version: buildPackages.runCommand "all-cabal-hashes-component-${name}-${version}" {} ''
     tar --wildcards -xzvf ${all-cabal-hashes} \*/${name}/${version}/${name}.{json,cabal}