Library /sys$common/syshlp/dbg$help.hlb DEBUG, Messages, THDSTACKOVER  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 thread thread_number's stack is close to overflowing

    Facility: DEBUG, VMS Debugger

    Explanation: This thread's stack is close to overflowing, it is
    over 66% full. Note that the debug kernel image runs on the user
    stacks, i.e. consumes user stack resources. Also the debug main
    image will run on the user stacks IF the debugger configuration
    is one process (DBG$PROCESS logical set to "NONE"). If a stack
    does overflow, memory errors, e.g. access violations, bus errors,
    segmentation faults, will likely occur.

    User Action: Your code may need to change to create this thread
    with a larger stack, see the Guide to POSIX Threads. Also always
    run the debugger in its DEFAULT or MULTIPROCESS configuration
    when debugging threaded applications.