del of exception causes Exception

[John Vandenberg]

The following code causes an exception

try:
    pass
except Exception as e:
    del e

$ python3.4 -m pyflakes test_del_exception.py
Traceback (most recent call last):
  File "/usr/lib64/python3.4/runpy.py", line 170, in _run_module_as_main
    "__main__", mod_spec)
  File "/usr/lib64/python3.4/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "/usr/lib/python3.4/site-packages/pyflakes-1.2.1-py3.4.egg/pyflakes/__main__.py", line 5, in <module>
    main(prog='pyflakes')
  File "/usr/lib/python3.4/site-packages/pyflakes-1.2.1-py3.4.egg/pyflakes/api.py", line 184, in main
    warnings = checkRecursive(args, reporter)
  File "/usr/lib/python3.4/site-packages/pyflakes-1.2.1-py3.4.egg/pyflakes/api.py", line 141, in checkRecursive
    warnings += checkPath(sourcePath, reporter)
  File "/usr/lib/python3.4/site-packages/pyflakes-1.2.1-py3.4.egg/pyflakes/api.py", line 108, in checkPath
    return check(codestr, filename, reporter)
  File "/usr/lib/python3.4/site-packages/pyflakes-1.2.1-py3.4.egg/pyflakes/api.py", line 69, in check
    w = checker.Checker(tree, filename)
  File "/usr/lib/python3.4/site-packages/pyflakes-1.2.1-py3.4.egg/pyflakes/checker.py", line 425, in __init__
    self.handleChildren(tree)
  File "/usr/lib/python3.4/site-packages/pyflakes-1.2.1-py3.4.egg/pyflakes/checker.py", line 747, in handleChildren
    self.handleNode(node, tree)
  File "/usr/lib/python3.4/site-packages/pyflakes-1.2.1-py3.4.egg/pyflakes/checker.py", line 794, in handleNode
    handler(node)
  File "/usr/lib/python3.4/site-packages/pyflakes-1.2.1-py3.4.egg/pyflakes/checker.py", line 1196, in TRY
    self.handleChildren(node, omit='body')
  File "/usr/lib/python3.4/site-packages/pyflakes-1.2.1-py3.4.egg/pyflakes/checker.py", line 747, in handleChildren
    self.handleNode(node, tree)
  File "/usr/lib/python3.4/site-packages/pyflakes-1.2.1-py3.4.egg/pyflakes/checker.py", line 794, in handleNode
    handler(node)
  File "/usr/lib/python3.4/site-packages/pyflakes-1.2.1-py3.4.egg/pyflakes/checker.py", line 1226, in EXCEPTHANDLER
    del self.scope[node.name]
KeyError: 'e'

This was introduced in 1.2.0 with https://github.com/pyflakes/pyflakes/commit/2a698f87c02a43d4489e30481e9def14ed4b4431

[Phil Frost (bitglue)]

Looks like this happens with Python 3 only.

[Phil Frost (bitglue)]

https://github.com/pyflakes/pyflakes/pull/67

[John Vandenberg (jayvdb)]

Yes, the new exception processing which causes this is Python 3 only