def settrace_forked():
    '''
    When creating a fork from a process in the debugger, we need to reset the whole debugger environment!
    '''
    host, port = dispatch()

    import pydevd_tracing
    pydevd_tracing.restore_sys_set_trace_func()

    if port is not None:
        global connected
        connected = False
        global forked
        forked = True

        custom_frames_container_init()

        settrace(
                host,
                port=port,
                suspend=False,
                trace_only_current_thread=False,
                overwrite_prev_trace=True,
                patch_multiprocessing=True,
        )

    When creating a fork from a process in the debugger, we need to reset the whole debugger environment!
    
debugger/src/pydevd.py