Compile fails with “file not found sdkconfig.h”
Another answer from the library docs:
If you see an error `file not found sdkconfig.h` then you're probably
hitting [this issue](https://github.com/espressif/arduino-esp32/pull/6962)
and need [this fix](https://github.com/espressif/arduino-esp32/pull/7330).
(`magic.sh setup` should create the appropriate `Arduino/hardware/espressif`
tree for you; you might need to delete the old version first.)