How can I get PHP to produce a backtrace upon errors?

Question

Trying to debug PHP using its default current-line-only error messages is horrible. How can I get PHP to produce a backtrace (stack trace) when errors are produced?

Answer 1

I just tried setting a session variable containing the contents of debug_backtrace() at the offending line, then printing it using register_shutdown_function(). Worked like a charm.