I am working on a module right now that is supposed to email me the details of any errors that happen in Magento (errors that throw the Magento error screen, and output a trace of the error). Getting the error itself is quite easy. The file for that is /app/code/core/Mage/Core/functions.php, with the method mageCoreErrorHandler(). What I can’t figure out is how to get the trace of the error. That seems to be output from this file: /errors/process.php, which I don’t believe able to be overridden by any custom modules.
If any of you have any ideas, please let me know. Otherwise, when I figure it out, I’ll post the solution.