Crash reports should include the minimum code needed to produce the crash.  Adding function calls that never happen because the arguments cannot be computed adds noise that obscures the problem.  Here, b"a"*0xFFFFFFFFFFFFFFF would require more memory that any current computer has.  Float and array are irrelevant.  On Windows, it freezes python.  A MemoryError would be nicer, but this may be "won't fix".