If it helps:
in ESP8266 ver. 2.0.0 was added abort in
here
cores/esp8266/core_esp8266_postmortem.c:

void abort() __attribute__((noreturn));

void abort(){
    // cause exception
    s_abort_called = true;
    do {
        *((int*)0) = 0;
    } while(true);
} 

i comment the lines in MySensors/core/MyMainESP8266.cpp and it compiled ok.

@hek My code is from GatewayESP8266.ino example in Mysensors 1.5, line 234.

i have been using wifi gateway with Domoticz controller without any problems until recentely. After the last update to beta version of the controller, the gateway crashes when the controller request gateway version:
Gateway startup complete.
Client 0: 0;0;3;0;2;

Exception (28):
epc1=0x4000bf80 epc2=0x00000000 epc3=0x00000000 excvaddr=0x00000000 depc=0x00000000

ctx: cont
sp: 3ffebf60 end: 3ffec1f0 offset: 01a0

I have tested with telnet client with the same request and it was ok. Then I saw that the request from controller was terminated with only <LF> and not with <CR><LF> and this is why it crashed. I have added the following to the sketch:

•    if (inChar == '\n')
    {  
      if (inputString[i].string[inputString[i].idx-1] != '\r') { // if the last char is not CR then add it
      inputString[i].string[inputString[i].idx++]='\r';
     }
      // a command was issued by the client
      // we will now try to send it to the actuator
  

and now it seems to work.
Is this the right way to go?
Thanks