Issue with use of Serial.printf() function

[ShaggyDog18]

if there is a Serial.printf() function in the code, it is compiled without any error;
However, the code is not uploaded into MCU and does not show any error message.
The compile and upload result looks like below, no error reported, just Upload Quit.Still the code is not actually uploaded to the MCU:

Artery ISP Programmer V3.0.01
Support USART and DFU
------------------------------------------------------------

DFU Connect......
Device:  AT32F403ACGU7    Flash:  1024 KB
PID:  70050347      BID:  4703    Version:  3.2
Device connected Successfully

Upload Quit.
Have a good day!