Lindsay Haisley writes:
Isn't Signal 11 generally an indication of a hardware (e.g. memory) failure?
No. This is what Windows calls a "general protection fault", and it means that you've attempted to access memory that the operating system thinks you shouldn't. Possibly the most common low-level cause is dereferencing a NULL pointer, but overruns of dynamically allocated buffers and randomized pointers are also frequently observed.
High-level causes include program bugs, requesting that the compiler do inappropriate optimizations, buggy compilers, and linking to buggy libraries.
Either way, it's not a Mailman bug. Python (like many other high-level languages) promises to be safe, and not be crashable. It does quite well at that (I don't think I've ever observed a released Python to crash because of a bug in code written by the Python developers for Python), but it can't make promises for aggressively optimized distributions, for libraries, or for compilers.