Hi
1. This error does not affect the operation of the program，If you are using the ESP32 development board, you can delete this code “gpio_install_isr_service(0);” (in “esp-who/components/modules/button/who_button.c, line 91”) to fix this error.

2. The human face recognition example does not print ...

Which libraries are missing? could you attach your error log?

Maybe you can build a mouth landmarks regression network, and use these landmarks to judge the state of the mouth