Consistent environments for subprocesses

richardsheridan · richardsheridan · commit 725f1b988492 · 2020-08-17T19:14:10.000-04:00
H/T @QuLogic
diff --git a/lib/matplotlib/tests/test_backend_tk.py b/lib/matplotlib/tests/test_backend_tk.py
@@ -62,7 +62,9 @@ def legitimate_quit():
     try:
         proc = subprocess.run(
             [sys.executable, "-c", script,],
-            env={**os.environ, "SOURCE_DATE_EPOCH": "0"},
+            env={**os.environ,
+                 "MPLBACKEND": "TkAgg",
+                 "SOURCE_DATE_EPOCH": "0"},
             timeout=_test_timeout,
             stdout=subprocess.PIPE,
             check=True,
@@ -149,7 +151,9 @@ def test_never_update():
     try:
         proc = subprocess.run(
             [sys.executable, "-c", script,],
-            env={**os.environ, "SOURCE_DATE_EPOCH": "0"},
+            env={**os.environ,
+                 "MPLBACKEND": "TkAgg",
+                 "SOURCE_DATE_EPOCH": "0"},
             timeout=_test_timeout,
             capture_output=True,
             universal_newlines=True,
