From 879fa969fed2a67acfc06c367ad40b2be98ae7f8 Mon Sep 17 00:00:00 2001
From: Nicolas Benes <nbenes.gh@xandea.de>
Date: Tue, 28 Mar 2023 03:01:02 +0200
Subject: [PATCH] PyQt5: enable parallel building

Port the workaround for parallel building from PyQt6 to PyQt5. The
initial workaround has been added in commit
1824a128a150d743f1c6614ae849ad64894057a1.
---
 pkgs/development/python-modules/pyqt/5.x.nix | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/pkgs/development/python-modules/pyqt/5.x.nix b/pkgs/development/python-modules/pyqt/5.x.nix
index aeb207d294e8..f43038fac296 100644
--- a/pkgs/development/python-modules/pyqt/5.x.nix
+++ b/pkgs/development/python-modules/pyqt/5.x.nix
@@ -55,6 +55,17 @@ buildPythonPackage rec {
     EOF
   '';
 
+  enableParallelBuilding = true;
+  # HACK: paralellize compilation of make calls within pyqt's setup.py
+  # pkgs/stdenv/generic/setup.sh doesn't set this for us because
+  # make gets called by python code and not its build phase
+  # format=pyproject means the pip-build-hook hook gets used to build this project
+  # pkgs/development/interpreters/python/hooks/pip-build-hook.sh
+  # does not use the enableParallelBuilding flag
+  postUnpack = ''
+    export MAKEFLAGS+="''${enableParallelBuilding:+-j$NIX_BUILD_CORES}"
+  '';
+
   outputs = [ "out" "dev" ];
 
   dontWrapQtApps = true;