From ba02fd0434ed92b7335f17c97af689b9db1413e0 Mon Sep 17 00:00:00 2001
From: Frederik Rietdijk <fridh@fridh.nl>
Date: Wed, 20 Apr 2022 21:20:50 +0200
Subject: [PATCH] python3: fix overriding of interpreters, closes #163639

Overriding the interpreters did not work correctly. When overriding
packages would end up twice in the build time closure: one corresponding
to the overridden interpreter and one corresponding to the original
interpreter. The reason is that the override was not applied to the
interpreters in the spliced package sets.
---
 .../interpreters/python/cpython/default.nix     | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/pkgs/development/interpreters/python/cpython/default.nix b/pkgs/development/interpreters/python/cpython/default.nix
index 97db4a9fffa8..23c85942ad70 100644
--- a/pkgs/development/interpreters/python/cpython/default.nix
+++ b/pkgs/development/interpreters/python/cpython/default.nix
@@ -49,7 +49,7 @@
 , enableLTO ? stdenv.is64bit && stdenv.isLinux
 , reproducibleBuild ? false
 , pythonAttr ? "python${sourceVersion.major}${sourceVersion.minor}"
-}:
+} @ inputs:
 
 # Note: this package is used for bootstrapping fetchurl, and thus
 # cannot use fetchpatch! All mutable patches (generated by GitHub or
@@ -83,7 +83,10 @@ let
 
   tzdataSupport = tzdata != null && passthru.pythonAtLeast "3.9";
 
-  passthru = passthruFun rec {
+  passthru = let
+    # When we override the interpreter we also need to override the spliced versions of the interpreter
+    override = attr: let python = attr.override (inputs // { self = python; }); in python;
+  in passthruFun rec {
     inherit self sourceVersion packageOverrides;
     implementation = "cpython";
     libPrefix = "python${pythonVersion}";
@@ -91,11 +94,11 @@ let
     pythonVersion = with sourceVersion; "${major}.${minor}";
     sitePackages = "lib/${libPrefix}/site-packages";
     inherit hasDistutilsCxxPatch;
-    pythonOnBuildForBuild = pkgsBuildBuild.${pythonAttr};
-    pythonOnBuildForHost = pkgsBuildHost.${pythonAttr};
-    pythonOnBuildForTarget = pkgsBuildTarget.${pythonAttr};
-    pythonOnHostForHost = pkgsHostHost.${pythonAttr};
-    pythonOnTargetForTarget = pkgsTargetTarget.${pythonAttr} or {};
+    pythonOnBuildForBuild = override pkgsBuildBuild.${pythonAttr};
+    pythonOnBuildForHost = override pkgsBuildHost.${pythonAttr};
+    pythonOnBuildForTarget = override pkgsBuildTarget.${pythonAttr};
+    pythonOnHostForHost = override pkgsHostHost.${pythonAttr};
+    pythonOnTargetForTarget = if lib.hasAttr pythonAttr pkgsTargetTarget then (override pkgsTargetTarget.${pythonAttr}) else {};
   };
 
   version = with sourceVersion; "${major}.${minor}.${patch}${suffix}";