Use Agg backend in pickle test subprocess

QuLogic · QuLogic · commit 4bb4dc7d9d47 · 2023-09-02T00:39:50.000-04:00
The main parent process is using Agg, so the subprocess should as well,
to be able to unpickle correctly.
diff --git a/lib/matplotlib/tests/test_pickle.py b/lib/matplotlib/tests/test_pickle.py
@@ -143,7 +143,7 @@ def test_pickle_load_from_subprocess(fig_test, fig_ref, tmp_path):
     proc = subprocess_run_helper(
         _pickle_load_subprocess,
         timeout=60,
-        extra_env={'PICKLE_FILE_PATH': str(fp)}
+        extra_env={'PICKLE_FILE_PATH': str(fp), 'MPLBACKEND': 'Agg'}
     )
 
     loaded_fig = pickle.loads(ast.literal_eval(proc.stdout))

Original file line number	Diff line number	Diff line change
`@@ -143,7 +143,7 @@ def test_pickle_load_from_subprocess(fig_test, fig_ref, tmp_path):`
`143`	`143`	`proc = subprocess_run_helper(`
`144`	`144`	`_pickle_load_subprocess,`
`145`	`145`	`timeout=60,`
`146`		`- extra_env={'PICKLE_FILE_PATH': str(fp)}`
	`146`	`+ extra_env={'PICKLE_FILE_PATH': str(fp), 'MPLBACKEND': 'Agg'}`
`147`	`147`	`)`
`148`	`148`
`149`	`149`	`loaded_fig = pickle.loads(ast.literal_eval(proc.stdout))`