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Debugging Octave: Difference between revisions
→Tools for debugging: __debug_octave__ is in released versions now
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If you run Octave from a build tree, execute <code>./run-octave -g</code> to start a gdb session that is prepared to run Octave (with the necessary environment correctly set up). Note that when Octave runs in GUI mode, it forks at startup on Linux and MacOS systems, so this method will only work if <code>gdb</code> correctly follows the process across the <code>fork</code> and <code>exec</code> system calls. | If you run Octave from a build tree, execute <code>./run-octave -g</code> to start a gdb session that is prepared to run Octave (with the necessary environment correctly set up). Note that when Octave runs in GUI mode, it forks at startup on Linux and MacOS systems, so this method will only work if <code>gdb</code> correctly follows the process across the <code>fork</code> and <code>exec</code> system calls. | ||
Alternatively, you can attach a debugger to a running Octave session. Current | Alternatively, you can attach a debugger to a running Octave session. Current versions of Octave include the command <code>__debug_octave__</code> to manage the details. Executing this command at the Octave prompt should open a separate window for a debugger session attached to the current Octave process. On Linux systems, the default terminal window is <code>gnome-terminal</code>. On MacOS systems, the default debugger is <code>lldb</code>. | ||
For some kinds of errors on some OS, the last approach might not be useful. The OS might kill the shell that runs gdb as soon as the spawning process (i.e. Octave) crashes. In that case, you can attach to Octave from an "independent" shell. Execute <code>getpid ()</code> in Octave and take note of the displayed *PID*. Open a shell and execute <code>gdb -p *PID*</code> (replace <code>*PID*</code> with the actual PID). On Windows, use the msys2 shell that can be started with the file <code>cmdshell.bat</code> in Octave's installation folder. | For some kinds of errors on some OS, the last approach might not be useful. The OS might kill the shell that runs gdb as soon as the spawning process (i.e. Octave) crashes. In that case, you can attach to Octave from an "independent" shell. Execute <code>getpid ()</code> in Octave and take note of the displayed *PID*. Open a shell and execute <code>gdb -p *PID*</code> (replace <code>*PID*</code> with the actual PID). On Windows, use the msys2 shell that can be started with the file <code>cmdshell.bat</code> in Octave's installation folder. | ||