2 files changed, 10 insertions, 2 deletions

diff --git a/bitbake/lib/bb/msg.py b/bitbake/lib/bb/msg.py
index 90b158238f..f1723be797 100644
--- a/bitbake/lib/bb/msg.py
+++ b/bitbake/lib/bb/msg.py
@@ -216,3 +216,10 @@ def logger_create(name, output=sys.stderr, level=logging.INFO, preserve_handlers
         logger.handlers = [console]
     logger.setLevel(level)
     return logger
+
+def has_console_handler(logger):
+    for handler in logger.handlers:
+        if isinstance(handler, logging.StreamHandler):
+            if handler.stream in [sys.stderr, sys.stdout]:
+                return True
+    return False
diff --git a/bitbake/lib/bb/ui/knotty.py b/bitbake/lib/bb/ui/knotty.py
index 82aa7c4644..a19c3b3ba5 100644
--- a/bitbake/lib/bb/ui/knotty.py
+++ b/bitbake/lib/bb/ui/knotty.py
@@ -365,8 +365,9 @@ def main(server, eventHandler, params, tf = TerminalFilter):
     bb.msg.addDefaultlogFilter(errconsole, bb.msg.BBLogFilterStdErr)
     console.setFormatter(format)
     errconsole.setFormatter(format)
-    logger.addHandler(console)
-    logger.addHandler(errconsole)
+    if not bb.msg.has_console_handler(logger):
+        logger.addHandler(console)
+        logger.addHandler(errconsole)
 
     bb.utils.set_process_name("KnottyUI")