From b1b6ccaee55c32e376923ddb965d882117c50b12 Mon Sep 17 00:00:00 2001
From: Hamish Mackenzie <Hamish.K.Mackenzie@gmail.com>
Date: Fri, 14 Feb 2025 18:55:08 +1300
Subject: [PATCH 1/2] Disable ghc docs by default

---
 compiler/ghc/default.nix | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/compiler/ghc/default.nix b/compiler/ghc/default.nix
index f72a3b8a95..583332c59e 100644
--- a/compiler/ghc/default.nix
+++ b/compiler/ghc/default.nix
@@ -52,6 +52,8 @@ let self =
 , # Wheter to build in NUMA support
   enableNUMA ? true
 
+, enableDocs ? false # Choose between --docs=none and --docs=no-sphinx
+
 , # What flavour to build. An empty string indicates no
   # specific flavour and falls back to ghc default values.
   ghcFlavour ? lib.optionalString haskell-nix.haskellLib.isCrossTarget (
@@ -317,7 +319,7 @@ let
           + lib.optionalString enableDWARF "+debug_info"
           + lib.optionalString ((enableNativeBignum && hadrianHasNativeBignumFlavour) || targetPlatform.isGhcjs) "+native_bignum"
           + lib.optionalString targetPlatform.isGhcjs "+no_profiled_libs"
-      } --docs=no-sphinx -j --verbose"
+      } --docs=${if enableDocs then "no-sphinx" else "none"} -j --verbose"
       # This is needed to prevent $GCC from emitting out of line atomics.
       # Those would then result in __aarch64_ldadd1_sync and others being referenced, which
       # we don't handle in the RTS properly yet. Until we figure out how to _properly_ deal

From 7ae0cd7f2098ad10e236977c8216cb2d9ce6f357 Mon Sep 17 00:00:00 2001
From: Hamish Mackenzie <Hamish.K.Mackenzie@gmail.com>
Date: Fri, 14 Feb 2025 19:22:03 +1300
Subject: [PATCH 2/2] Add a comment

---
 compiler/ghc/default.nix | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/compiler/ghc/default.nix b/compiler/ghc/default.nix
index 583332c59e..52e1a76a5f 100644
--- a/compiler/ghc/default.nix
+++ b/compiler/ghc/default.nix
@@ -53,6 +53,15 @@ let self =
   enableNUMA ? true
 
 , enableDocs ? false # Choose between --docs=none and --docs=no-sphinx
+                     # Turning this off saves around 600MB for each GHC build
+                     # If you need GHC docs use an overlay like this:
+                     #   final: prev: {
+                     #     haskell-nix = prev.haskell-nix // {
+                     #       compiler = final.lib.mapAttrs (_: x: x.override ({
+                     #         enableDocs = true;
+                     #       })) prev.haskell-nix.compiler;
+                     #     };
+                     #   }
 
 , # What flavour to build. An empty string indicates no
   # specific flavour and falls back to ghc default values.