tests: workaround logfile closing race

Author: ksedgwic

contrib/pyln-testing/pyln/testing/fixtures.py

@@ -94,6 +94,9 @@ def directory(request, test_base_dir, test_name):
 
     if not failed and not bool(int(os.getenv('TEST_KEEPDIR', '0'))):
         try:
+            # We are removing the log files before the processes are done logging ...
+            # we don't seem to get the OSError, instead stderr gets spammed
+            time.sleep(10)
             shutil.rmtree(directory)
         except OSError:
             # Usually, this means that e.g. valgrind is still running.  Wait