sim: Mock sys.print_exception

It doesn't exist in CPython.

sim/run.py

@@ -9,6 +9,7 @@ import os
 import sys
 import builtins
 import argparse
+import traceback
 
 
 projectpath = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
@@ -128,6 +129,9 @@ def _stat(path):
 os.stat = _stat
 
 
+sys.print_exception = lambda x: print(traceback.format_exc())
+
+
 def sim_main():
     parser = argparse.ArgumentParser()
     parser.add_argument(