CommandResult's lazy vals get null value when remote command throwing a "SEGV" as exitSignal

[thomassun]

the lazy vals(exitCode,exitErrorMessage, i/o streams etc.) gives null instead of Option for the channel as result of a remote command causes "Segmentation fault" or "Floating point exception" where the exception stored in exitSignal
it's easy to reproduce, just compile following c code and run it's binary with exec and then access the exitCode, it throws java.lang.NullPointerException

int main(int argc, char *argv[]){
int x;
x = 100/0;
}