circular stack at frame address frame-addr

    Facility: DEBUG, VMS Debugger

    Explanation: The debugger is attempting to chain down the call
    stack, following frame pointers. The debugger has determined that
    the linked frames loop back on themselves at frame-addr.

    User Action: Determine what part of your code is writing into the
    FP register or overwriting the saved frame pointer on the call
    stack (or a preceding saved frame pointer) and correct it. Since
    the debugger looks at the call stack to symbolize addresses, you
    may suppress some of these messages by typing the command "SET
    MODE NOSYMBOLIC".