knotty: stop freaking out and dying when bb.build has removed the empty logfile

(Bitbake rev: 2197182fe5837d74f1499c644e882e87cf035238)

Signed-off-by: Chris Larson <chris_larson@mentor.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>

bitbake/lib/bb/ui/knotty.py

@@ -94,7 +94,7 @@ def init(server, eventHandler):
             if isinstance(event, bb.build.TaskFailed):
                 return_value = 1
                 logfile = event.logfile
-                if logfile:
+                if logfile and os.path.exists(logfile):
                     print("ERROR: Logfile of failure stored in: %s" % logfile)
                     if 1 or includelogs:
                         print("Log data follows:")