This does appear to be a bug of some sort.
Unfortunately, the symbols are not showing in that backtrace. Because of how this works on Linux, we can’t really extract them from the core necessarily. If you have a core file available, can you open it in gdb (usually, the easiest way to be sure it resolves the symbols is to start gdb from the directory where moxi’s binary is) and get a backtrace of all threads?