When using static TAG is only valid in the current compile unit. For
some reason it seems that the current ESP8266/ESP32 compiler use the
instance from ble.cpp, but it seems that this causes issues with newer
compiler leading to compile time errors like this:
In file included from /root/.platformio/packages/framework-arduinoespressif32/cores/esp32/esp32-hal-log.h:164,
from /root/.platformio/packages/framework-arduinoespressif32/cores/esp32/esp32-hal.h:71,
from /root/.platformio/packages/framework-arduinoespressif32/cores/esp32/Arduino.h:36,
from src/esphome/core/esphal.h:3,
from src/esphome/core/helpers.h:10,
from src/esphome/components/esp32_ble/ble_uuid.h:3,
from src/esphome/components/esp32_ble/ble_advertising.cpp:5:
src/esphome/components/esp32_ble/ble_advertising.cpp: In member function 'void esphome::esp32_ble::BLEAdvertising::start()':
src/esphome/components/esp32_ble/ble_advertising.cpp:64:14: error: 'TAG' was not declared in this scope
ESP_LOGE(TAG, "esp_ble_gap_config_adv_data failed (Advertising): %d", err);
^~~
Stefan Agner