.pio\libdeps\esp32dev\Adafruit BME680 Library\Adafruit_BME680.cpp: In member function ‘bool Adafruit_BME680::endReading()’:
.pio\libdeps\esp32dev\Adafruit BME680 Library\Adafruit_BME680.cpp:418:20: warning: overflow in implicit constant conversion [-Woverflow]
gas_resistance = NAN;
The gas sensor isn’t even in this code. My guess is that it’s something in the library.
This is a warning, not an error.
Whatever data type the variable
gas_resistance is, it cannot accomodate the value
NAN which is used when a floating point number cannot be held in the data tyoe used.
See http://www.cplusplus.com/reference/cmath/NAN/ for details.
In this case, it can probably be ignored. I imagine the code is initialising the variable with a “not used yet” type of value which will be overwritten when the gas sensor is used.