I got too myself some boards. XI is indeed a 382 clone, but it seems that the XI core library is missing yield() functionality.
I managed to compile my mysensors sketch with first forcing the
#define ARDUINO_ARCH_AVR in the sketch and
with some modifications at the XI core library:
- I added the
void yield(void);somewhere in ..\ARDUINO\hardware\wemos\XI\cores\lgt8f\Arduino.h
- I added the hooks.c file to ..\ARDUINO\hardware\wemos\XI\cores\lgt8f\ from https://github.com/arduino/Arduino/blob/master/hardware/arduino/avr/cores/arduino/hooks.c
However i did not yet upload the sketch to the board, I'll later when I get home.