If I run my code using 'python -m' and there is an unhandled exception, the tracebacks include lines from runpy.py (and now sometimes from importlib._bootstrap) which don't provide useful information, and tend to overwhelm the valuable part of the traceback.

I suppose this is in some sense a regression from Python 2.4.


echo fail > fail.py
python3.3 -m fail

python -m fail
Traceback (most recent call last):
  File "/usr/lib/python3.3/runpy.py", line 160, in _run_module_as_main
    "__main__", fname, loader, pkg_name)
  File "/usr/lib/python3.3/runpy.py", line 73, in _run_code
    exec(code, run_globals)
  File "./fail.py", line 2, in <module>
    fail
NameError: name 'fail' is not defined

Here I think it would be better to omit the first two traceback entries.


Syntax errors are worse:
echo syntax error > fail.py
python3.3 -m fail

Traceback (most recent call last):
  File "/usr/lib/python3.3/runpy.py", line 140, in _run_module_as_main
    mod_name, loader, code, fname = _get_module_details(mod_name)
  File "/usr/lib/python3.3/runpy.py", line 114, in _get_module_details
    code = loader.get_code(mod_name)
  File "<frozen importlib._bootstrap>", line 981, in get_code
  File "<frozen importlib._bootstrap>", line 313, in _call_with_frames_removed
  File "./fail.py", line 1
    syntax error

Here there are four traceback entries which could be omitted.