human
Solve the following python programming problem given the following code:
@ WebApp.route ('/logs/<build>/') 
@ auth_required 
def log_file(request, build) : 
    data_dir = request.app.app.data_dir 
    filename = os.path.join (data_dir, thread, 'log.txt') 
    levelno = request.values.get ('levelno', default = logging.INFO, type = int) 
    thread = request.values.get ('thread') 
    logger = request.values.get ('name') 
    def records() : 
        with open (filename) as f : 
            for (number, line) in enumerate (f) : 
                if (not line.strip ()) : 
                    continue 
try : 
                    record = json.loads (line) 
except Exception : 
                    record = { 
                        'parsing_error' : traceback.format_exc (), 
                        'line_number' : (number + 1), 
} 
else : 
                    if (logger and (not record ['name'].startswith (logger))) : 
                        continue 
if (record ['levelno'] < levelno) : 
                        continue 
if (thread and (thread != ((record ['process_name'] + '/') + record ['thread_name']))) : 
                        continue 
record ['created_time'] = time.gmtime (record ['created']) 
                    record ['created_string'] = time.strftime ('%Y-%m-%d %H:%M:%S', record ['created_time']) 
(yield record) 
return render (request, records (), 'log_file', build = build, records = records (), levelno = levelno) 

    
    

    Fix the buggy line: filename = os.path.join (data_dir, thread, 'log.txt')
assistant
#Here is Python code to fix the buggy line: filename = os.

filename = os.path.join (data_dir, build, 'log.txt')