testing: don't spam stderr when the log file is closed

contrib/pyln-testing/pyln/testing/utils.py

@@ -865,12 +865,16 @@ def __init__(self, socket_path, executor=None, logger=logging,
     def call(self, method, payload=None, cmdprefix=None, filter=None):
         id = self.get_json_id(method, cmdprefix)
         schemas = self.jsonschemas.get(method)
-        self.logger.debug(json.dumps({
-            "id": id,
-            "method": method,
-            "params": payload,
-            "filter": filter,
-        }, indent=2))
+        # Sometimes our log file is closed, don't spam stderr in this case
+        try:
+            self.logger.debug(json.dumps({
+                "id": id,
+                "method": method,
+                "params": payload,
+                "filter": filter,
+            }, indent=2))
+        except ValueError:
+            pass
 
         # We only check payloads which are dicts, which is what we
         # usually use: there are some cases which tests [] params,