# Buggy code
def debug_cache_stats():
    """Print LRU cache stats."""
    prefix_info = configdata.is_valid_prefix.cache_info()
    # pylint: disable=protected-access
    render_stylesheet_info = config._render_stylesheet.cache_info()
    # pylint: enable=protected-access

    history_info = None
    try:
        from PyQt5.QtWebKit import QWebHistoryInterface

        interface = QWebHistoryInterface.defaultInterface()
        if interface is not None:
            history_info = interface.historyContains.cache_info()
    except ImportError:
        pass

    tabbed_browser = objreg.get("tabbed-browser", scope="window", window="last-focused")
    # pylint: disable=protected-access
    tab_bar = tabbed_browser.tabBar()
    tabbed_browser_info = tab_bar._minimum_tab_size_hint_helper.cache_info()
    # pylint: enable=protected-access

    log.misc.debug("is_valid_prefix: {}".format(prefix_info))
    log.misc.debug("_render_stylesheet: {}".format(render_stylesheet_info))
    log.misc.debug("history: {}".format(history_info))
    log.misc.debug("tab width cache: {}".format(tabbed_browser_info))


# 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 debug_cache_stats():
    """Print LRU cache stats."""
    prefix_info = configdata.is_valid_prefix.cache_info()
    # pylint: disable=protected-access
    render_stylesheet_info = config._render_stylesheet.cache_info()
    # pylint: enable=protected-access

    history_info = None
    try:
        from PyQt5.QtWebKit import QWebHistoryInterface

        interface = QWebHistoryInterface.defaultInterface()
        if interface is not None:
            history_info = interface.historyContains.cache_info()
    except ImportError:
        pass

    tabbed_browser = objreg.get("tabbed-browser", scope="window", window="last-focused")
    # pylint: disable=protected-access
    tab_bar = tabbed_browser.widget.tabBar()
    tabbed_browser_info = tab_bar._minimum_tab_size_hint_helper.cache_info()
    # pylint: enable=protected-access

    log.misc.debug("is_valid_prefix: {}".format(prefix_info))
    log.misc.debug("_render_stylesheet: {}".format(render_stylesheet_info))
    log.misc.debug("history: {}".format(history_info))
    log.misc.debug("tab width cache: {}".format(tabbed_browser_info))