From cc22c861e805952b75941d467d826a70a7063a80 Mon Sep 17 00:00:00 2001
From: Adam Joseph <adam@westernsemico.com>
Date: Thu, 15 Jun 2023 18:04:46 -0700
Subject: [PATCH 1/2] glibc: allow users of glibc/common.nix to override
 makeFlags

This commit allows to include `makeFlags` in a glibc derivation
without clobbering the flags from `common.nix`
---
 pkgs/development/libraries/glibc/common.nix | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pkgs/development/libraries/glibc/common.nix b/pkgs/development/libraries/glibc/common.nix
index de9867f41d0de24..f98c0eb1c3487cd 100644
--- a/pkgs/development/libraries/glibc/common.nix
+++ b/pkgs/development/libraries/glibc/common.nix
@@ -161,7 +161,7 @@ stdenv.mkDerivation ({
     ++ lib.optional withGd "--with-gd"
     ++ lib.optional (!withLibcrypt) "--disable-crypt";
 
-  makeFlags = [
+  makeFlags = (args.makeFlags or []) ++ [
     "OBJCOPY=${stdenv.cc.targetPrefix}objcopy"
   ];
 
@@ -196,7 +196,7 @@ stdenv.mkDerivation ({
   passthru = { inherit version; minorRelease = version; };
 }
 
-// (removeAttrs args [ "withLinuxHeaders" "withGd" "postInstall" ]) //
+// (removeAttrs args [ "withLinuxHeaders" "withGd" "postInstall" "makeFlags" ]) //
 
 {
   src = fetchurl {

From b243596eb72f12d5280447b9b817b9aa6f8e9f43 Mon Sep 17 00:00:00 2001
From: Adam Joseph <adam@westernsemico.com>
Date: Thu, 15 Jun 2023 18:33:39 -0700
Subject: [PATCH 2/2] glibcLocales: use more than one core to build

This commit massively reduces the build latency for glibcLocales by
allowing it to build in parallel.  This requires passing
`-j$NIX_BUILD_CORES` via the glibc-specific make variable
`PARALLELMFLAGS`.

This commit also fixes a preexisting bug where the glibcLocales
package would ignore `preBuild` and `postBuild`.
---
 pkgs/development/libraries/glibc/locales.nix | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/pkgs/development/libraries/glibc/locales.nix b/pkgs/development/libraries/glibc/locales.nix
index ed6f0a5b32ca80e..22572a003859246 100644
--- a/pkgs/development/libraries/glibc/locales.nix
+++ b/pkgs/development/libraries/glibc/locales.nix
@@ -10,8 +10,9 @@
 , allLocales ? true, locales ? [ "en_US.UTF-8/UTF-8" ]
 }:
 
-callPackage ./common.nix { inherit stdenv; } {
+(callPackage ./common.nix { inherit stdenv; } {
   pname = "glibc-locales";
+}).overrideAttrs(finalAttrs: previousAttrs: {
 
   builder = ./locales-builder.sh;
 
@@ -25,7 +26,7 @@ callPackage ./common.nix { inherit stdenv; } {
     else "--big-endian")
   ];
 
-  buildPhase = ''
+  preBuild = (previousAttrs.preBuild or "") + ''
       # Awful hack: `localedef' doesn't allow the path to `locale-archive'
       # to be overriden, but you *can* specify a prefix, i.e. it will use
       # <prefix>/<path-to-glibc>/lib/locale/locale-archive.  So we use
@@ -57,11 +58,15 @@ callPackage ./common.nix { inherit stdenv; } {
       fi
 
       echo SUPPORTED-LOCALES='${toString locales}' > ../glibc-2*/localedata/SUPPORTED
-    '' + ''
-      make localedata/install-locales \
-          localedir=$out/lib/locale \
     '';
 
+  makeFlags = (previousAttrs.makeFlags or []) ++ [
+    "localedata/install-locales"
+    "localedir=${builtins.placeholder "out"}/lib/locale"
+  ] ++ lib.optionals finalAttrs.finalPackage.enableParallelInstalling [
+    "PARALLELMFLAGS=-j$(NIX_BUILD_CORES)"
+  ];
+
   installPhase =
     ''
       mkdir -p "$out/lib/locale" "$out/share/i18n"
@@ -75,4 +80,4 @@ callPackage ./common.nix { inherit stdenv; } {
     '';
 
   meta.description = "Locale information for the GNU C Library";
-}
+})