Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/apt/cache.py", line 198, in __getitem__
    return self._weakref[key]
  File "/usr/lib/python3.4/weakref.py", line 125, in __getitem__
    o = self.data[key]()
KeyError: 'libharfbuzz0b:i386'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 113, in _apt_pkg
    return self._cache()[package]
  File "/usr/lib/python3/dist-packages/apt/cache.py", line 205, in __getitem__
    raise KeyError('The cache has no package named %r' % key)
KeyError: "The cache has no package named 'libharfbuzz0b:i386'"

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/apport/report.py", line 197, in _run_hook
    symb['add_info'](report, ui)
  File "/usr/share/apport/general-hooks/ubuntu.py", line 129, in add_info
    if conflict_pkg and not apport.packaging.is_distro_package(conflict_pkg.group(1)):
  File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 175, in is_distro_package
    pkg = self._apt_pkg(package)
  File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 115, in _apt_pkg
    raise ValueError('package %s does not exist' % package)
ValueError: package libharfbuzz0b:i386 does not exist