From 629af6c9da8cdcb8253a2a9d345ebf1281f745e4 Mon Sep 17 00:00:00 2001
From: Matt Sturgeon <[email protected]>
Date: Thu, 15 Jan 2026 11:27:10 +0000
Subject: [PATCH 1/2] tests.eval: check buildPythonPackage fixpoint args
 warning

---
 pkgs/test/eval/default.nix | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pkgs/test/eval/default.nix b/pkgs/test/eval/default.nix
index 5eb709bab139..08fc6587aec8 100644
--- a/pkgs/test/eval/default.nix
+++ b/pkgs/test/eval/default.nix
@@ -70,6 +70,7 @@ runCommand "nixpkgs-pkgs-tests-eval"
       overridePythonAttrs-stdenv-deprecated
       overridePythonAttrs-override-clangStdenv-deprecated-nested
       buildPythonPackage-stdenv-deprecated
+      buildPythonPackage-fp-args-stdenv-deprecated
     )
     expected_warning='evaluation warning: python-package-stub: Passing `stdenv` directly to `buildPythonPackage` or `buildPythonApplication` is deprecated.'
 
-- 
2.52.0

From ff90863b81c129fb07d342056dd1dd5148f7976b Mon Sep 17 00:00:00 2001
From: Matt Sturgeon <[email protected]>
Date: Thu, 15 Jan 2026 11:36:29 +0000
Subject: [PATCH 2/2] buildPython*: include package name in fixpoint-args
 stdenv warning

In the simple case we attempt to get a name from the input args, as this
avoids evaluating the initial `result`.

In the fixpoint-args scenario, this isn't possible. Therefore, we should
extract the name from `result`.
---
 .../python/python-packages-base.nix           | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/pkgs/development/interpreters/python/python-packages-base.nix b/pkgs/development/interpreters/python/python-packages-base.nix
index 9537844d10a8..b62ec897de87 100644
--- a/pkgs/development/interpreters/python/python-packages-base.nix
+++ b/pkgs/development/interpreters/python/python-packages-base.nix
@@ -55,24 +55,27 @@ let
         args:
         let
           result = f args;
-          applyMsgStdenvArg = 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; } { }
-          '';
+          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 then
           if result ? __stdenvPythonCompat then
             # Less reliable, as constructing with the wrong `stdenv` might lead to evaluation errors in the package definition.
-            f'.override { stdenv = applyMsgStdenvArg result.__stdenvPythonCompat; } (
+            f'.override { stdenv = applyMsgStdenvArg (getName result) result.__stdenvPythonCompat; } (
               finalAttrs: removeAttrs (args finalAttrs) [ "stdenv" ]
             )
           else
             result
         else if args ? stdenv then
           # More reliable, but only works when args is not `(finalAttrs: { })`
-          f'.override { stdenv = applyMsgStdenvArg args.stdenv; } (removeAttrs args [ "stdenv" ])
+          f'.override { stdenv = applyMsgStdenvArg (getName args) args.stdenv; } (
+            removeAttrs args [ "stdenv" ]
+          )
         else
           result
       )
-- 
2.52.0