Fix QNX test abort in release builds and pushbuild, avoid killing our

#  cluck("Called mtr_exit()");

  mtr_timer_stop_all($::glob_timers);

  local $SIG{HUP} = 'IGNORE';

  kill('HUP', -$$);

  # ToDo: Signalling -$$ will only work if we are the process group

  # leader (in fact on QNX it will signal our session group leader,

  # which might be Do-compile or Pushbuild, causing tests to be

  # aborted). So we only do it if we are the group leader. We might

  # set ourselves as the group leader at startup (with

  # POSIX::setpgrp(0,0)), but then care must be needed to always do

  # proper child process cleanup.

  kill('HUP', -$$) if $$ == getpgrp();

  sleep 2;

  exit($code);

}