/usr/bin/twistd3 fails with "AttributeError: module 'sys' has no attribute 'exc_clear'"

[Ricardo Bánffy]

When attempting to start a Twisted-based application, it incurred in the following error:

Traceback (most recent call last):
  File "/usr/bin/twistd", line 9, in <module>
    sys.exc_clear()
AttributeError: module 'sys' has no attribute 'exc_clear'
Traceback (most recent call last):
  File "/usr/bin/twistd", line 7, in <module>
    import _preamble
ImportError: No module named '_preamble'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/bin/twistd", line 9, in <module>
    sys.exc_clear()
AttributeError: module 'sys' has no attribute 'exc_clear'
Traceback (most recent call last):
  File "/usr/bin/twistd", line 7, in <module>
    import _preamble
ImportError: No module named '_preamble'

This is fixed on upstream https://twistedmatrix.com/trac/browser/trunk/bin/twistd

Running Ubuntu Xenial with python3-twisted-experimental version "15.4.0-0ubuntu2"

[Leonardo Donelli (learts92)]

The bug is still present in Trusty.