From 896e11b507aad6532a21d30af0ec329ccafb7958 Mon Sep 17 00:00:00 2001
From: Stefan Frijters <sfrijters@gmail.com>
Date: Wed, 25 Feb 2026 11:39:12 +0100
Subject: [PATCH] qt6.qtbase: fix incorrect substitution in setupHook

---
 .../development/libraries/qt-6/hooks/qtbase-setup-hook.sh | 8 ++++----
 .../development/libraries/qt-6/modules/qtbase/default.nix | 7 +++++++
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/pkgs/development/libraries/qt-6/hooks/qtbase-setup-hook.sh b/pkgs/development/libraries/qt-6/hooks/qtbase-setup-hook.sh
index c70bf22759de1..f2cbd39ac6cd7 100644
--- a/pkgs/development/libraries/qt-6/hooks/qtbase-setup-hook.sh
+++ b/pkgs/development/libraries/qt-6/hooks/qtbase-setup-hook.sh
@@ -1,13 +1,13 @@
 if [[ -n "${__nix_qtbase-}" ]]; then
     # Throw an error if a different version of Qt was already set up.
-    if [[ "$__nix_qtbase" != "@out@" ]]; then
+    if [[ "$__nix_qtbase" != "@qtbaseOut@" ]]; then
         echo >&2 "Error: detected mismatched Qt dependencies:"
-        echo >&2 "    @out@"
+        echo >&2 "    @qtbaseOut@"
         echo >&2 "    $__nix_qtbase"
         exit 1
     fi
 else # Only set up Qt once.
-    __nix_qtbase="@out@"
+    __nix_qtbase="@qtbaseOut@"
 
     qtPluginPrefix=@qtPluginPrefix@
     qtQmlPrefix=@qtQmlPrefix@
@@ -16,7 +16,7 @@ else # Only set up Qt once.
     . @fix_qt_module_paths@
 
     # Build tools are often confused if QMAKE is unset.
-    export QMAKE=@out@/bin/qmake
+    export QMAKE=@qtbaseOut@/bin/qmake
 
     export QMAKEPATH=
 
diff --git a/pkgs/development/libraries/qt-6/modules/qtbase/default.nix b/pkgs/development/libraries/qt-6/modules/qtbase/default.nix
index 040041f93b3c8..710c572ac59cf 100644
--- a/pkgs/development/libraries/qt-6/modules/qtbase/default.nix
+++ b/pkgs/development/libraries/qt-6/modules/qtbase/default.nix
@@ -321,6 +321,13 @@ stdenv.mkDerivation {
     moveToOutput      "mkspecs/modules" "$dev"
     fixQtModulePaths  "$dev/mkspecs/modules"
     fixQtBuiltinPaths "$out" '*.pr?'
+
+    # @out@ would be automagically replaced inside makeSetupHook by the output of that derivation,
+    # but we need it to be the output of this derivation.
+    # Use a different placeholder and explicitly substitute this
+    # to keep compatibility with __structuredAttrs and avoid substituteAll.
+    substituteInPlace "''${!outputDev}/nix-support/setup-hook" \
+      --replace-fail "@qtbaseOut@" $out
   ''
   + lib.optionalString stdenv.hostPlatform.isLinux ''
     # FIXME: not sure why this isn't added automatically?