Make a GC run before trying to clean up files left over by
the latest test run.
diff --git a/Lib/test/regrtest.py b/Lib/test/regrtest.py
index 958582a..c4f1c8a 100755
--- a/Lib/test/regrtest.py
+++ b/Lib/test/regrtest.py
@@ -978,6 +978,12 @@
def cleanup_test_droppings(testname, verbose):
import shutil
import stat
+ import gc
+
+ # First kill any dangling references to open files etc.
+ # This can also issue some ResourceWarnings which would otherwise get
+ # triggered during the following test run, and possible produce failures.
+ gc.collect()
# Try to clean up junk commonly left behind. While tests shouldn't leave
# any files or directories behind, when a test fails that can be tedious