From 9f3e8a9f0b97939c5cc79f98842db3b7940954ed Mon Sep 17 00:00:00 2001
From: Reno Dakota <170618376+paparodeo@users.noreply.github.com>
Date: Wed, 23 Oct 2024 20:16:59 +0000
Subject: [PATCH] python312Packages.pytest-mpl: fix darwin

fix checkphase on darwin to not access the display by using a workaround
for matplotlib:
https://github.com/matplotlib/matplotlib/issues/26292#issuecomment-1632887774
---
 pkgs/development/python-modules/pytest-mpl/default.nix | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/pkgs/development/python-modules/pytest-mpl/default.nix b/pkgs/development/python-modules/pytest-mpl/default.nix
index 26cca96a3d42..d5bfa4402cbe 100644
--- a/pkgs/development/python-modules/pytest-mpl/default.nix
+++ b/pkgs/development/python-modules/pytest-mpl/default.nix
@@ -43,10 +43,13 @@ buildPythonPackage rec {
     "tests/subtests/test_subtest.py"
   ];
 
+  # need to set MPLBACKEND=agg for headless matplotlib for darwin
+  # https://github.com/matplotlib/matplotlib/issues/26292
   # The default tolerance is too strict in our build environment
   # https://github.com/matplotlib/pytest-mpl/pull/9
   # https://github.com/matplotlib/pytest-mpl/issues/225
   preCheck = ''
+    export MPLBACKEND=agg
     substituteInPlace pytest_mpl/plugin.py \
       --replace-fail "DEFAULT_TOLERANCE = 2" "DEFAULT_TOLERANCE = 10"
     substituteInPlace tests/test_pytest_mpl.py \