TST: try to fix windows by directly setting mplbackend env

tacaswell · tacaswell · commit 70ad7f7a5fa5 · 2019-10-28T00:14:34.000-04:00
diff --git a/lib/matplotlib/tests/test_backend_webagg.py b/lib/matplotlib/tests/test_backend_webagg.py
@@ -5,7 +5,9 @@
 
 @pytest.mark.parametrize('backend', ['webagg', 'nbagg'])
 def test_webagg_fallback(backend):
-    test_code = ("import matplotlib.pyplot as plt; " +
+    test_code = ("import os;" +
+                 f"os.environ['MPLBACKEND'] = '{backend}';" +
+                 "import matplotlib.pyplot as plt; " +
                  "print(plt.get_backend());"
                  f"assert '{backend}' == plt.get_backend().lower();")
     ret = subprocess.call(
