# Buggy code
def __init__(self, *, win_id, mode_manager, private, parent=None):
    self.private = private
    self.win_id = win_id
    self.tab_id = next(tab_id_gen)
    super().__init__(parent)

    self.registry = objreg.ObjectRegistry()
    tab_registry = objreg.get("tab-registry", scope="window", window=win_id)
    tab_registry[self.tab_id] = self
    objreg.register("tab", self, registry=self.registry)

    self.data = TabData()
    self._layout = miscwidgets.WrapperLayout(self)
    self._widget = None
    self._progress = 0
    self._has_ssl_errors = False
    self._mode_manager = mode_manager
    self._load_status = usertypes.LoadStatus.none
    self._mouse_event_filter = mouse.MouseEventFilter(self, parent=self)
    self.backend = None

    # FIXME:qtwebengine  Should this be public api via self.hints?
    #                    Also, should we get it out of objreg?
    hintmanager = hints.HintManager(win_id, self.tab_id, parent=self)
    objreg.register(
        "hintmanager", hintmanager, scope="tab", window=self.win_id, tab=self.tab_id
    )

    self.predicted_navigation.connect(
        lambda url: self.title_changed.emit(url.toDisplayString())
    )


# Traceback (ValueError)
16:39:44 DEBUG    init       app:_init_modules:468 Initializing websettings...
16:39:45 ERROR    misc       crashsignal:exception_hook:216 Uncaught exception
Traceback (most recent call last):
File "/bin/qutebrowser", line 11, in <module>
load_entry_point('qutebrowser==1.1.1', 'gui_scripts', 'qutebrowser')()
File "/usr/lib/python3.6/site-packages/qutebrowser/qutebrowser.py", line 188, in main
return app.run(args)
File "/usr/lib/python3.6/site-packages/qutebrowser/app.py", line 137, in run
init(args, crash_handler)
File "/usr/lib/python3.6/site-packages/qutebrowser/app.py", line 163, in init
_init_modules(args, crash_handler)
File "/usr/lib/python3.6/site-packages/qutebrowser/app.py", line 469, in _init_modules
websettings.init(args)
File "/usr/lib/python3.6/site-packages/qutebrowser/config/websettings.py", line 215, in init
webenginesettings.init(args)
File "/usr/lib/python3.6/site-packages/qutebrowser/browser/webengine/webenginesettings.py", line 297, in init
websettings.init_mappings(MAPPINGS)
File "/usr/lib/python3.6/site-packages/qutebrowser/config/websettings.py", line 198, in init_mappings
mapping.set(value)
File "/usr/lib/python3.6/site-packages/qutebrowser/config/websettings.py", line 72, in set
self._set(value, settings=settings)
File "/usr/lib/python3.6/site-packages/qutebrowser/browser/webengine/webenginesettings.py", line 154, in _set
filenames = [self._find_installed(code) for code in value]
File "/usr/lib/python3.6/site-packages/qutebrowser/browser/webengine/webenginesettings.py", line 154, in <listcomp>
filenames = [self._find_installed(code) for code in value]
File "/usr/lib/python3.6/site-packages/qutebrowser/browser/webengine/webenginesettings.py", line 143, in _find_installed
local_filename = spell.local_filename(code)
File "/usr/lib/python3.6/site-packages/qutebrowser/browser/webengine/spell.py", line 64, in local_filename
all_installed = local_files(code)
File "/usr/lib/python3.6/site-packages/qutebrowser/browser/webengine/spell.py", line 51, in local_files
for matching_dict in sorted(matching_dicts, key=version, reverse=True):
File "/usr/lib/python3.6/site-packages/qutebrowser/browser/webengine/spell.py", line 36, in version
.format(filename))
ValueError: the given dictionary file name is malformed: /usr/share/qt/qtwebengine_dictionaries/en-US.bdic

# Fixed code
def __init__(self, *, win_id, mode_manager, private, parent=None):
    self.private = private
    self.win_id = win_id
    self.tab_id = next(tab_id_gen)
    super().__init__(parent)

    self.registry = objreg.ObjectRegistry()
    tab_registry = objreg.get("tab-registry", scope="window", window=win_id)
    tab_registry[self.tab_id] = self
    objreg.register("tab", self, registry=self.registry)

    self.data = TabData()
    self._layout = miscwidgets.WrapperLayout(self)
    self._widget = None
    self._progress = 0
    self._has_ssl_errors = False
    self._mode_manager = mode_manager
    self._load_status = usertypes.LoadStatus.none
    self._mouse_event_filter = mouse.MouseEventFilter(self, parent=self)
    self.backend = None

    # FIXME:qtwebengine  Should this be public api via self.hints?
    #                    Also, should we get it out of objreg?
    hintmanager = hints.HintManager(win_id, self.tab_id, parent=self)
    objreg.register(
        "hintmanager", hintmanager, scope="tab", window=self.win_id, tab=self.tab_id
    )

    self.predicted_navigation.connect(self._on_predicted_navigation)