I2C clock streching on esp8266.

I was hoping I could use JsError as in the file jshardware.c, where the call come from, maybe someone has a solution.

you can't use JsError in i2c_master.c

use os_printf() or os_printf_plus(), both write to debug log

than use ESP8266.setLog(2); in the js code to switch debug log to uart0 (console)