Bug: słownik języka polskiego engine

[return42]

Version of SearXNG, commit number if you are using on master branch and stipulate if you forked SearXNG
Repository: https://github.com/searxng/searxng
Branch: master
Version: current master

How did you install SearXNG?

make run

What happened?

ERROR   werkzeug                      : Error on request:
Traceback (most recent call last):
  File "local/py3/lib/python3.8/site-packages/werkzeug/serving.py", line 335, in run_wsgi
    execute(self.server.app)
  File "local/py3/lib/python3.8/site-packages/werkzeug/serving.py", line 325, in execute
    write(data)
  File "local/py3/lib/python3.8/site-packages/werkzeug/serving.py", line 265, in write
    self.send_header(key, value)
  File "/usr/lib/python3.8/http/server.py", line 517, in send_header
    ("%s: %s\r\n" % (keyword, value)).encode('latin-1', 'strict'))
UnicodeEncodeError: 'latin-1' codec can't encode character '\u0142' in position 61: ordinal not in range(256)

How To Reproduce

query !słownik_języka_polskiego foo

Screenshots & Logs

I debugged by adding a try/except and pdb ...

(Pdb) l
259  	                except ValueError:
260  	                    code_str, msg = status_sent, ""
261  	                code = int(code_str)
262  	                self.send_response(code, msg)
263  	                header_keys = set()
264  ->	                for key, value in headers_sent:
265  	                    try:
266  	                        self.send_header(key, value)
267  	                        header_keys.add(key.lower())
268  	                    except Exception as exc:
269  	                        import pdb
(Pdb) key
'Server-Timing'
(Pdb) value
'total;dur=289.618, render;dur=105.459, total_0_słownik języka polskiego;dur=174.954, load_0_słownik języka polskiego;dur=165.832'

... the name słownik języka polskiego can't be encoded in latin-1.

(Pdb) where
  /usr/lib/python3.8/threading.py(890)_bootstrap()
-> self._bootstrap_inner()
  /usr/lib/python3.8/threading.py(932)_bootstrap_inner()
-> self.run()
  /usr/lib/python3.8/threading.py(870)run()
-> self._target(*self._args, **self._kwargs)
  /usr/lib/python3.8/socketserver.py(683)process_request_thread()
-> self.finish_request(request, client_address)
  /usr/lib/python3.8/socketserver.py(360)finish_request()
-> self.RequestHandlerClass(request, client_address, self)
  /usr/lib/python3.8/socketserver.py(747)__init__()
-> self.handle()
  local/py3/lib/python3.8/site-packages/werkzeug/serving.py(367)handle()
-> super().handle()
  /usr/lib/python3.8/http/server.py(427)handle()
-> self.handle_one_request()
  /usr/lib/python3.8/http/server.py(415)handle_one_request()
-> method()
  local/py3/lib/python3.8/site-packages/werkzeug/serving.py(339)run_wsgi()
-> execute(self.server.app)
  local/py3/lib/python3.8/site-packages/werkzeug/serving.py(329)execute()
-> write(data)
> local/py3/lib/python3.8/site-packages/werkzeug/serving.py(264)write()
-> for key, value in headers_sent:

Additional context

Unicode characters (not ASCII) in the name of an engine always cause problems, e.g. in logging, another example is #166

Technical report

Its a severe issue .. no technical report is generated, the entire process fails.