Create loop if not already running

Author: Carreau

tests/test_eventloop.py

@@ -83,7 +83,11 @@ def test_asyncio_loop(kernel):
     def do_thing():
         loop.call_later(0.01, loop.stop)
 
-    loop = asyncio.get_event_loop()
+    try:
+        loop = asyncio.get_event_loop()
+    except RuntimeError:
+        loop = asyncio.new_event_loop()
+        asyncio.set_event_loop(loop)
     loop.call_soon(do_thing)
     loop_asyncio(kernel)
 
@@ -128,7 +132,10 @@ def test_qt_enable_gui(kernel, capsys):
 
     enable_gui(not_gui, kernel)
     captured = capsys.readouterr()
-    assert captured.out == f"Cannot switch Qt versions for this session; you must use {gui}.\n"
+    assert (
+        captured.out
+        == f"Cannot switch Qt versions for this session; you must use {gui}.\n"
+    )
 
     # Check 'qt' gui, which means "the best available"
     enable_gui(None, kernel)