HP gnu source-level debugger 5992-4701 - Manual (Page 194)

Behavior of the +check=thread option can be changed by users by providing their
own rtcconfig file. The user specified rtcconfig file can be in the current directory
or in a directory specified by the GDBRTC_CONFIG environment variable.
If any thread error condition is detected during the application run, the error log will
be output to a file in the current working directory. The output file will have the
following naming convention:
..threads,
where is the process identifier.
14.11.7 Known issues with Thread Debugging for Interactive and Batch mode
Issue 1:
During the execution of advanced thread checking for applications that fork, in the
interactive mode, the following message appears if the GDB follows the child:
Pthread analysis file missing!
This error message appears because the thread-error information for the forked process
is not available.
However, if the forked process exec()s another binary, the thread-error information
is available for the exec -ed binary.
Issue 2
In both interactive and batch modes, if the applications exceed their thread stack
utilization, the following error message appears:
Error accessing memory address
This occurs when GDB attempts a command line call on an already overflowing thread
stack.
14.12 Debugging MPI Programs
You can attach the debugger to Message Passing Interface (MPI) programs for
debugging. You must set the one of the following environment variables before you
launch the MPI process:
set MPI_FLAGS= egdb for invoking GDB
or
set MPI_FLAGS= ewdb for invoking WDB
For more information, see the mpidebug(1) and mpienv(1) manpages.
Attaching the debugger to an MPI process (or to any other process that has not been
compiled for debugging) can result in the following warning:
warning: reading 'r3' register: No data
194 HP-UX Configuration-Specific Information