Hi, Since the end of last december, I'm still working on my fault handler project: https://github.com/haypo/faulthandler
You can use it to get more information after a crash or if you program hangs somewhere. It helps if you don't have access to other debugging tool (eg. install gdb7+python-gdb.py on Windows is not trivial today) or if you cannot interact with your program (eg. on a buildbot). The last version works on Python 2.5, 2.6, 2.7, 3.1 and 3.2, on Windows, Linux and FreeBSD. It can display the Python backtrace on a fatal fault (SIGSEGV, SIGFPE, SIGILL, SIGBUS), after a delay in seconds, when an user signal is received (eg. SIGUSR1) or explicitly (call directly the dumpbacktrace() function). By default, it is disabled: you have to call faulthandler.enable() to install the signal handlers. You can choose in which file the backtrace is written (sys.stderr by default) and if it displays the backtrace of the current thread or of all threads. If you use the delay: you can choose to repeat the operation (dump the backtrace each delay seconds). The project is now a module, so it is no more enabled by default. It is more configurable, and has more features. It has a better API (so it was a good idea to not include it in Python 3.2). I plan to integrate this project into Python 3.3. I hope that it can help to debug some buildbots issues, but also any segfault in your programs. Note: faulthandler.register() (dump the backtrace when an user signal is raised) is only available in the development version. -- The project is not perfect yet: - I have to write something to be able to enable the faulthandler before starting your program (write a program for that?) - faulthandler.dumpbacktrace_later() uses alarm() which interrupts the current system call when SIGALARM is raised: it may be a problem (it's maybe not a problem if you try to debug a program hang) - I don't know if something should be done on a fork() - SIGABRT is not handled - The module is unloaded using Py_AtExit(): it cannot release references because the unload function is called too late -- There are similar projects, tipper and crier, using a signal handler implemented in Python or a signal handler implemented in Python. These projects give more information (eg. local variables) and more control on how the informations are written, but I think that there are less reliable: it doesn't work if Python hangs (eg. deadlock) and signal handlers implemented in Python are asynchronous. And there are unable to catch fatal faults (eg. SIGSEGV). http://pypi.python.org/pypi/tipper/ https://gist.github.com/737056 Victor _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
