The value of the logical name DBG$PROCESS determines the
    debugging configuration as follows:

    DBG$PROCESS
    Definition             Configuration

    DEFAULT or undefined   Default
    MULTIPROCESS           Multiprocess

    Use the default configuration to debug programs that normally run
    (without the debugger) in only one process. Use the multiprocess
    configuration to debug programs that normally run in more than
    one process.

    When defining DBG$PROCESS for a multiprocess configuration, make
    the definition job wide. This ensures that any processes that are
    in the same job tree as the program being debugged (for example,
    processes spawned by the program) can be controlled from the same
    debugging session.

    For more information, see help on Debugging_Configurations.