[Python-Dev] Issue #8863 adds a new PYTHONNOFAULTHANDLER environment variable

[Victor Stinner]

Hi,

In 2008, I proposed a patch to raise a Python exception on SIGSEVG 
signal. In some cases, it's possible to catch the exception, log it, and 
continue the execution. But because in some cases, the Python internal 
state is corrupted, the idea was rejected (see the issue #3999).

Someone asked me to display the Python backtrace on SIGSEGV, instead of 
raising an exception. I implemented this idea in issue #8863. After 9 
versions, I think that the patch is ready for inclusion. It catchs 
SIGSEGV, SIGFPE, SIGBUS and SIGILL signals, and also display the Python 
backtrace on fatal errors. Because some operating systems have their own 
fault handler (eg. Ubuntu with apport), Dave Malcolm asked me to add an 
option disable the Python handler. That's why I added the 
PYTHONNOFAULTHANDLER environment variable (we all love long variable 
names!). For an OS vendor, it looks like an environment variable is more 
practical than a command line option. Eg. Mandriva sets 
PYTHONDONTWRITEBYTECODE for the whole system.

Raymond Hettinger asked me on IRC to write an email about the new 
environment variable, so here is the question: do you agree to add the 
new variable?

Victor