tools: Redirect some warnings to stderr

components/app_update/otatool.py

@@ -250,9 +250,9 @@ def _erase_ota_partition(target, ota_id):
 
 def main():
     if sys.version_info[0] < 3:
-        print("WARNING: Support for Python 2 is deprecated and will be removed in future versions.")
+        print("WARNING: Support for Python 2 is deprecated and will be removed in future versions.", file=sys.stderr)
     elif sys.version_info[0] == 3 and sys.version_info[1] < 6:
-        print("WARNING: Python 3 versions older than 3.6 are not supported.")
+        print("WARNING: Python 3 versions older than 3.6 are not supported.", file=sys.stderr)
     global quiet
 
     parser = argparse.ArgumentParser("ESP-IDF OTA Partitions Tool")

components/spiffs/spiffsgen.py

@@ -453,9 +453,9 @@ class SpiffsFS():
 
 def main():
     if sys.version_info[0] < 3:
-        print("WARNING: Support for Python 2 is deprecated and will be removed in future versions.")
+        print("WARNING: Support for Python 2 is deprecated and will be removed in future versions.", file=sys.stderr)
     elif sys.version_info[0] == 3 and sys.version_info[1] < 6:
-        print("WARNING: Python 3 versions older than 3.6 are not supported.")
+        print("WARNING: Python 3 versions older than 3.6 are not supported.", file=sys.stderr)
     parser = argparse.ArgumentParser(description="SPIFFS Image Generator",
                                      formatter_class=argparse.ArgumentDefaultsHelpFormatter)