Return a list of pages to index

def process_all_json_files(build_dir):
    """Return a list of pages to index"""
    html_files = []
    for root, _, files in os.walk(build_dir):
        for filename in fnmatch.filter(files, '*.fjson'):
            if filename in ['search.fjson', 'genindex.fjson',
                            'py-modindex.fjson']:
                continue
            html_files.append(os.path.join(root, filename))
    page_list = []
    for filename in html_files:
        try:
            result = process_file(filename)
            if result:
                page_list.append(result)
        # we're unsure which exceptions can be raised
        except:  # noqa
            pass
    return page_list