#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/wait.h>
#include <sys/ptrace.h>
#include <fcntl.h>
#include <unistd.h>
#include <paths.h>
#include <err.h>
#include <termios.h>
#include <signal.h>
#include <stdio.h>

int
main(int argc, char **argv)
{
        int status;
        pid_t child, wpid;

        child = fork();
        if (child == -1)
                err(1, "fork");
        if (child == 0) {
                setpgrp(0, 0);

#if 1
                ptrace(PT_TRACE_ME, 0, NULL, 0);
                raise(SIGSTOP);
#endif
#if 1
                pid_t child2;
                child2 = fork();
                if (child2 == 0)
                        raise(SIGSTOP);
#endif

                raise(SIGSTOP);
                __builtin_trap();
        }

        wpid = waitpid(child, &status, WSTOPPED);
        if (wpid == -1)
                err(1, "wait");
        if (wpid != child)
                err(1, "wpid != child");

#if 1
        ptrace_event_t pe;
        pe.pe_set_event |= PTRACE_FORK;
        ptrace(PT_SET_EVENT_MASK, child, &pe, sizeof(pe));
#endif
#if 1
        ptrace(PT_CONTINUE, child, (void *)1, 0);

        wpid = waitpid(child, &status, WSTOPPED);
        if (wpid == -1)
                err(1, "wait");
        if (wpid != child)
                err(1, "wpid != child");
#endif

        return 0;
}