fix: don't use closed stderr when launching driver process (microsoft#1100)

AlberLC · web-flow · commit c16481b678e0 · 2022-01-13T23:53:55.000+01:00
Fixes microsoft#1098
diff --git a/playwright/_impl/_transport.py b/playwright/_impl/_transport.py
@@ -33,6 +33,9 @@
 
 # Sourced from: https://github.com/pytest-dev/pytest/blob/da01ee0a4bb0af780167ecd228ab3ad249511302/src/_pytest/faulthandler.py#L69-L77
 def _get_stderr_fileno() -> Optional[int]:
+    if sys.stderr.closed:
+        return None
+
     try:
         return sys.stderr.fileno()
     except (AttributeError, io.UnsupportedOperation):
