app/drivers/led.c: In function 'led_init':
app/drivers/led.c:42:2: error: 'x' is used uninitialized in this function [-Werror=uninitialized]
led_tx_set(x);
^~~~~~~~~~~~~
cc1: all warnings being treated as errors
make: *** [out/obj/app/drivers/led.o] Error 1
make: *** Waiting for unfinished jobs....
The command "CFLAGS=-Werror make -j2" exited with 2.
Done. Your build exited with 1.
Seems to work fine. Added a test warning: