From d5d41ef1a0efad1e87acd36c9b33789f127dd487 Mon Sep 17 00:00:00 2001
From: Christian Decker <decker.christian@gmail.com>
Date: Wed, 7 Oct 2020 10:41:36 +0200
Subject: [PATCH] pyln: Remove any logging handlers at teardown to avoid
 logging error

Inspired by https://github.com/pytest-dev/pytest/issues/5502#issuecomment-647157873
---
 contrib/pyln-testing/pyln/testing/fixtures.py | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/contrib/pyln-testing/pyln/testing/fixtures.py b/contrib/pyln-testing/pyln/testing/fixtures.py
index f13dcfb7b..a68dd8988 100644
--- a/contrib/pyln-testing/pyln/testing/fixtures.py
+++ b/contrib/pyln-testing/pyln/testing/fixtures.py
@@ -40,14 +40,25 @@ def test_base_dir():
 
 @pytest.fixture(autouse=True)
 def setup_logging():
-    logger = logging.getLogger()
-    before_handlers = list(logger.handlers)
+    """Enable logging before a test, and remove all handlers afterwards.
 
+    This "fixes" the issue with pytest swapping out sys.stdout and sys.stderr
+    in order to capture the output, but then doesn't wait for the handlers to
+    terminate before closing the buffers. It just iterates through all
+    loggers, and removes any handlers that might be pointing at sys.stdout or
+    sys.stderr.
+
+    """
     if TEST_DEBUG:
         logging.basicConfig(level=logging.DEBUG, stream=sys.stdout)
 
     yield
-    logger.handlers = before_handlers
+
+    loggers = [logging.getLogger()] + list(logging.Logger.manager.loggerDict.values())
+    for logger in loggers:
+        handlers = getattr(logger, 'handlers', [])
+        for handler in handlers:
+            logger.removeHandler(handler)
 
 
 @pytest.fixture