bitbake: event.py: output errors and warnings to stderr

All logging messages are printed on stdout when processing
UI event queue. This makes it impossible to distinguish between
errors and normal bitbake output. Output to stderror or stdout
depending on log level should fix this.

(Bitbake rev: c4029c4f00197804511fc71e1190d34eb120212a)

Signed-off-by: Ed Bartosh <ed.bartosh@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/event.py

@@ -117,21 +117,28 @@ def print_ui_queue():
     logger = logging.getLogger("BitBake")
     if not _uiready:
         from bb.msg import BBLogFormatter
-        console = logging.StreamHandler(sys.stdout)
-        console.setFormatter(BBLogFormatter("%(levelname)s: %(message)s"))
-        logger.handlers = [console]
+        stdout = logging.StreamHandler(sys.stdout)
+        stderr = logging.StreamHandler(sys.stderr)
+        formatter = BBLogFormatter("%(levelname)s: %(message)s")
+        stdout.setFormatter(formatter)
+        stderr.setFormatter(formatter)
 
         # First check to see if we have any proper messages
         msgprint = False
         for event in ui_queue:
             if isinstance(event, logging.LogRecord):
                 if event.levelno > logging.DEBUG:
+                    if event.levelno >= logging.WARNING:
+                        logger.handlers = [stderr]
+                    else:
+                        logger.handlers = [stdout]
                     logger.handle(event)
                     msgprint = True
         if msgprint:
             return
 
         # Nope, so just print all of the messages we have (including debug messages)
+        logger.handlers = [stdout]
         for event in ui_queue:
             if isinstance(event, logging.LogRecord):
                 logger.handle(event)