Merge pull request #5653 from rtthread-bot/rtt_bot

[update] RT-Thread Robot automatic submission

Author: Guozhanxin

tools/gcc.py

@@ -113,7 +113,7 @@ def checkAndGetResult(pattern, string):
         stdout, stderr = child.communicate()
 
         # print(stdout)
-        if stderr != '':
+        if stderr != '' and stderr != b'':
             print(stderr)
 
         have_fdset = 0