From 4ef0c2ded41c446cd8cd2611554487363e28ee15 Mon Sep 17 00:00:00 2001
From: Yueh-Shun Li <shamrocklee@posteo.net>
Date: Mon, 5 Jan 2026 15:33:29 +0800
Subject: [PATCH 1/3] buildPython*: overrideStdenvCompat: abstract warning

Co-authored-by: Matt Sturgeon <matt@sturgeon.me.uk>
---
 .../python/python-packages-base.nix            | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/pkgs/development/interpreters/python/python-packages-base.nix b/pkgs/development/interpreters/python/python-packages-base.nix
index 91d733a33c3e..74ae67e1b563 100644
--- a/pkgs/development/interpreters/python/python-packages-base.nix
+++ b/pkgs/development/interpreters/python/python-packages-base.nix
@@ -53,13 +53,19 @@ let
       f':
       lib.mirrorFunctionArgs f (
         args:
+        let
+          getName = x: x.pname or (lib.getName (x.name or "<unnamed>"));
+          applyMsgStdenvArg =
+            name:
+            lib.warnIf (lib.oldestSupportedReleaseIsAtLeast 2511) ''
+              ${name}: Passing `stdenv` directly to `buildPythonPackage` or `buildPythonApplication` is deprecated. You should use their `.override` function instead, e.g:
+                buildPythonPackage.override { stdenv = customStdenv; } { }
+            '';
+        in
         if !(lib.isFunction args) && (args ? stdenv) then
-          lib.warnIf (lib.oldestSupportedReleaseIsAtLeast 2511) ''
-            ${
-              args.name or args.pname or "<unnamed>"
-            }: Passing `stdenv` directly to `buildPythonPackage` or `buildPythonApplication` is deprecated. You should use their `.override` function instead, e.g:
-              buildPythonPackage.override { stdenv = customStdenv; } { }
-          '' (f'.override { inherit (args) stdenv; } (removeAttrs args [ "stdenv" ]))
+          applyMsgStdenvArg (getName args) (
+            f'.override { inherit (args) stdenv; } (removeAttrs args [ "stdenv" ])
+          )
         else
           f args
       )

From 5b114f0534d820d60186d402e8964b64d67e810e Mon Sep 17 00:00:00 2001
From: Yueh-Shun Li <shamrocklee@posteo.net>
Date: Mon, 5 Jan 2026 15:37:43 +0800
Subject: [PATCH 2/3] buildPython*: overrideStdenvCompat: lower warnings down
 to the stdenv override value

If Nix supports lazy attribute names in the future,
this change will make `<python package>.override` warning-free
and make such warning (or future throw) remediateable
via another override.
---
 pkgs/development/interpreters/python/python-packages-base.nix | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pkgs/development/interpreters/python/python-packages-base.nix b/pkgs/development/interpreters/python/python-packages-base.nix
index 74ae67e1b563..1fe5fcbaf60e 100644
--- a/pkgs/development/interpreters/python/python-packages-base.nix
+++ b/pkgs/development/interpreters/python/python-packages-base.nix
@@ -63,8 +63,8 @@ let
             '';
         in
         if !(lib.isFunction args) && (args ? stdenv) then
-          applyMsgStdenvArg (getName args) (
-            f'.override { inherit (args) stdenv; } (removeAttrs args [ "stdenv" ])
+          f'.override { stdenv = applyMsgStdenvArg (getName args) args.stdenv; } (
+            removeAttrs args [ "stdenv" ]
           )
         else
           f args

From de48b6a845e7f206d8c11075a507814b6b5d13c7 Mon Sep 17 00:00:00 2001
From: Yueh-Shun Li <shamrocklee@posteo.net>
Date: Mon, 5 Jan 2026 16:06:56 +0800
Subject: [PATCH 3/3] buildPython*: extend overrideStdenvCompat to fixed-point
 arguments

with `passthru.__stdenvPythonCompat`

Co-authored-by: Matt Sturgeon <matt@sturgeon.me.uk>
---
 .../interpreters/python/mk-python-derivation.nix      |  1 +
 .../interpreters/python/python-packages-base.nix      | 11 +++++++++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/pkgs/development/interpreters/python/mk-python-derivation.nix b/pkgs/development/interpreters/python/mk-python-derivation.nix
index f3e5249c189e..0fb0a1326025 100644
--- a/pkgs/development/interpreters/python/mk-python-derivation.nix
+++ b/pkgs/development/interpreters/python/mk-python-derivation.nix
@@ -418,6 +418,7 @@ lib.extendMkDerivation {
           optional-dependencies
           ;
         updateScript = nix-update-script { };
+        ${if attrs ? stdenv then "__stdenvPythonCompat" else null} = attrs.stdenv;
       }
       // attrs.passthru or { };
 
diff --git a/pkgs/development/interpreters/python/python-packages-base.nix b/pkgs/development/interpreters/python/python-packages-base.nix
index 1fe5fcbaf60e..77ac26630161 100644
--- a/pkgs/development/interpreters/python/python-packages-base.nix
+++ b/pkgs/development/interpreters/python/python-packages-base.nix
@@ -54,6 +54,7 @@ let
       lib.mirrorFunctionArgs f (
         args:
         let
+          result = f args;
           getName = x: x.pname or (lib.getName (x.name or "<unnamed>"));
           applyMsgStdenvArg =
             name:
@@ -62,12 +63,18 @@ let
                 buildPythonPackage.override { stdenv = customStdenv; } { }
             '';
         in
-        if !(lib.isFunction args) && (args ? stdenv) then
+        if lib.isFunction args && result ? __stdenvPythonCompat then
+          # Less reliable, as constructing with the wrong `stdenv` might lead to evaluation errors in the package definition.
+          f'.override { stdenv = applyMsgStdenvArg (getName result) result.__stdenvPythonCompat; } (
+            finalAttrs: removeAttrs (args finalAttrs) [ "stdenv" ]
+          )
+        else if (!lib.isFunction args) && (args ? stdenv) then
+          # More reliable, but only works when args is not `(finalAttrs: { })`
           f'.override { stdenv = applyMsgStdenvArg (getName args) args.stdenv; } (
             removeAttrs args [ "stdenv" ]
           )
         else
-          f args
+          result
       )
       // {
         # Preserve the effect of overrideStdenvCompat when calling `buildPython*.override`.