ValueError: SMAZ can only process ASCII text

[lopuhin]

I thought this could not possibly happen, but somehow non-ascii URLs can reach SMAZ:

Traceback (most recent call last):
  File "/usr/local/lib/python3.5/site-packages/twisted/internet/task.py", line 517, in _oneWorkUnit
    result = next(self._iterator)
  File "/usr/local/lib/python3.5/site-packages/scrapy/utils/defer.py", line 63, in <genexpr>
    work = (callable(elem, *args, **named) for elem in iterable)
  File "/usr/local/lib/python3.5/site-packages/scrapy/core/scraper.py", line 183, in _process_spidermw_output
    self.crawler.engine.crawl(request=output, spider=spider)
  File "/usr/local/lib/python3.5/site-packages/scrapy/core/engine.py", line 210, in crawl
    self.schedule(request, spider)
  File "/usr/local/lib/python3.5/site-packages/scrapy/core/engine.py", line 216, in schedule
    if not self.slot.scheduler.enqueue_request(request):
  File "/usr/local/lib/python3.5/site-packages/scrapy_redis/scheduler.py", line 167, in enqueue_request
    self.queue.push(request)
  File "/dd_crawler/dd_crawler/queue.py", line 90, in push
    data = self._encode_request(request)
  File "/dd_crawler/dd_crawler/queue.py", line 392, in _encode_request
    return struct.pack('h', depth) + parent + url_compress(request.url)
  File "/dd_crawler/dd_crawler/queue.py", line 374, in url_compress
    return smaz.compress(url, compression_tree=smaz_tree).encode('latin1')
  File "/usr/local/lib/python3.5/site-packages/lib/smaz.py", line 399, in compress
    raise ValueError('SMAZ can only process ASCII text.')
ValueError: SMAZ can only process ASCII text