From 159a6daf6b6eafd1bb0179a9ee88fca3c3318f75 Mon Sep 17 00:00:00 2001
From: Eman Resu <78693624+quatquatt@users.noreply.github.com>
Date: Thu, 28 May 2026 13:24:29 -0400
Subject: [PATCH] stdenv/generic: memoise passing config to mkDerivation unless
 overriden

---
 pkgs/stdenv/darwin/default.nix  |  9 +++------
 pkgs/stdenv/freebsd/default.nix |  8 ++++----
 pkgs/stdenv/generic/default.nix | 21 ++++++++++++++++++---
 pkgs/stdenv/linux/default.nix   |  9 +++++----
 pkgs/stdenv/native/default.nix  |  5 +++--
 pkgs/stdenv/nix/default.nix     |  8 ++++----
 6 files changed, 37 insertions(+), 23 deletions(-)

diff --git a/pkgs/stdenv/darwin/default.nix b/pkgs/stdenv/darwin/default.nix
index 3cf47e5a7334..48c2db483e4a 100644
--- a/pkgs/stdenv/darwin/default.nix
+++ b/pkgs/stdenv/darwin/default.nix
@@ -27,6 +27,7 @@ assert crossSystem == localSystem;
 
 let
   inherit (localSystem) system;
+  genericStdenv = import ../generic { defaultConfig = config; };
 
   llvmVersion = "21"; # This needs to be updated when the default LLVM version is changed.
   sdkMajorVersion = lib.versions.major localSystem.darwinSdkVersion;
@@ -104,15 +105,13 @@ let
 
       bashNonInteractive = prevStage.bashNonInteractive or bootstrapTools;
 
-      thisStdenv = import ../generic {
+      thisStdenv = genericStdenv {
         name = "${name}-stdenv-darwin";
 
         buildPlatform = localSystem;
         hostPlatform = localSystem;
         targetPlatform = localSystem;
 
-        inherit config;
-
         extraBuildInputs = [ prevStage.apple-sdk ];
         inherit extraNativeBuildInputs;
 
@@ -975,15 +974,13 @@ assert bootstrapTools.passthru.isFromBootstrapFiles or false; # sanity check
     in
     {
       inherit config overlays;
-      stdenv = import ../generic {
+      stdenv = genericStdenv {
         name = "stdenv-darwin";
 
         buildPlatform = localSystem;
         hostPlatform = localSystem;
         targetPlatform = localSystem;
 
-        inherit config;
-
         preHook = ''
           ${commonPreHook}
           stripDebugFlags="-S" # llvm-strip does not support "-p" for Mach-O
diff --git a/pkgs/stdenv/freebsd/default.nix b/pkgs/stdenv/freebsd/default.nix
index 046039d1ffbe..7ede014f80f1 100644
--- a/pkgs/stdenv/freebsd/default.nix
+++ b/pkgs/stdenv/freebsd/default.nix
@@ -21,6 +21,8 @@
 
 assert crossSystem == localSystem;
 let
+  genericStdenv = import ../generic { defaultConfig = config; };
+
   inherit (localSystem) system;
   mkExtraBuildCommands0 = cc: ''
     rsrc="$out/resource-root"
@@ -383,9 +385,8 @@ let
         bsdcp
       ];
       shell = "${prevStage.bashNonInteractive}/bin/bash";
-      stdenvNoCC = import ../generic {
+      stdenvNoCC = genericStdenv {
         inherit
-          config
           initialPath
           shell
           fetchurlBoot
@@ -401,9 +402,8 @@ let
         inherit (prevStage) curl;
         inherit (config) hashedMirrors rewriteURL;
       };
-      stdenv = import ../generic {
+      stdenv = genericStdenv {
         inherit
-          config
           initialPath
           shell
           fetchurlBoot
diff --git a/pkgs/stdenv/generic/default.nix b/pkgs/stdenv/generic/default.nix
index 6fa172b9a0fd..95d9228d7da2 100644
--- a/pkgs/stdenv/generic/default.nix
+++ b/pkgs/stdenv/generic/default.nix
@@ -1,6 +1,20 @@
+{
+  defaultConfig ? null,
+}@args:
 let
   lib = import ../../../lib;
+
+  # By taking defaultConfig early, we can cache the result of calling
+  # make-derivation.nix with config, which leads to more memoisation between
+  # bootstrapping stages. We only have to re-call the file with another config
+  # if stdenv-overridable is actually called with config, otherwise we stick to
+  # defaultConfig. No stdenvs currently specify a non-default config, but we
+  # leave it open as a possibility.
   makeDerivationFile = import ./make-derivation.nix lib;
+  makeDerivationFileWithConfig =
+    assert args ? defaultConfig;
+    makeDerivationFile args.defaultConfig;
+
   defaultNativeBuildInputs0 = [
     ../../build-support/setup-hooks/no-broken-symlinks.sh
     ../../build-support/setup-hooks/audit-tmpdir.sh
@@ -39,7 +53,7 @@ let
       allowedRequisites ? null,
       extraAttrs ? { },
       overrides ? (self: super: { }),
-      config,
+      config ? args.defaultConfig,
       disallowedRequisites ? [ ],
 
       # The `fetchurl' to use for downloading curl and its dependencies
@@ -83,9 +97,10 @@ let
       # This is convenient to have as a parameter so the stdenv "adapters" work better
       mkDerivationFromStdenv ?
         let
-          makeDerivationWithConfig = makeDerivationFile config;
+          makeDerivationWithConfig' =
+            if argsStdenv ? config then makeDerivationFile config else makeDerivationFileWithConfig;
         in
-        stdenv: (makeDerivationWithConfig stdenv).mkDerivation,
+        stdenv: (makeDerivationWithConfig' stdenv).mkDerivation,
     }:
 
     let
diff --git a/pkgs/stdenv/linux/default.nix b/pkgs/stdenv/linux/default.nix
index d8c9470e5dfa..feb7f90a147f 100644
--- a/pkgs/stdenv/linux/default.nix
+++ b/pkgs/stdenv/linux/default.nix
@@ -121,6 +121,8 @@
 assert crossSystem == localSystem;
 
 let
+  genericStdenv = import ../generic { defaultConfig = config; };
+
   inherit (localSystem) system;
 
   isFromNixpkgs = pkg: !(isFromBootstrapFiles pkg);
@@ -174,12 +176,12 @@ let
     }:
 
     let
-      thisStdenv = import ../generic {
+      thisStdenv = genericStdenv {
         name = "${name}-stdenv-linux";
         buildPlatform = localSystem;
         hostPlatform = localSystem;
         targetPlatform = localSystem;
-        inherit config extraNativeBuildInputs;
+        inherit extraNativeBuildInputs;
         inherit (stage0) initialPath;
         preHook = ''
           # Don't patch #!/interpreter because it leads to retained
@@ -696,13 +698,12 @@ in
     assert isBuiltByNixpkgsCompiler prevStage.patchelf;
     {
       inherit config overlays;
-      stdenv = import ../generic rec {
+      stdenv = genericStdenv rec {
         name = "stdenv-linux";
 
         buildPlatform = localSystem;
         hostPlatform = localSystem;
         targetPlatform = localSystem;
-        inherit config;
 
         preHook = commonPreHook;
 
diff --git a/pkgs/stdenv/native/default.nix b/pkgs/stdenv/native/default.nix
index a4b2ca42b780..697e593e205a 100644
--- a/pkgs/stdenv/native/default.nix
+++ b/pkgs/stdenv/native/default.nix
@@ -10,6 +10,8 @@
 assert crossSystem == localSystem;
 
 let
+  genericStdenv = import ../generic { defaultConfig = config; };
+
   inherit (localSystem) system;
 
   shell =
@@ -105,7 +107,7 @@ let
       extraNativeBuildInputs ? [ ],
     }:
 
-    import ../generic {
+    genericStdenv {
       buildPlatform = localSystem;
       hostPlatform = localSystem;
       targetPlatform = localSystem;
@@ -145,7 +147,6 @@ let
         shell
         cc
         overrides
-        config
         ;
     };
 
diff --git a/pkgs/stdenv/nix/default.nix b/pkgs/stdenv/nix/default.nix
index 59e67960aef1..84998fa52581 100644
--- a/pkgs/stdenv/nix/default.nix
+++ b/pkgs/stdenv/nix/default.nix
@@ -9,15 +9,15 @@
 }:
 
 assert crossSystem == localSystem;
-
+let
+  genericStdenv = import ../generic { defaultConfig = config; };
+in
 bootStages
 ++ [
   (prevStage: {
     inherit config overlays;
 
-    stdenv = import ../generic rec {
-      inherit config;
-
+    stdenv = genericStdenv rec {
       inherit (prevStage.stdenv) buildPlatform hostPlatform targetPlatform;
 
       preHook = ''