Handle Mimic missing properly

[forslund]

Description

I got an error report on chat with the following error:

Traceback (most recent call last):
  File "/home/roy/mycroft-core/mycroft/tts/tts.py", line 519, in create
    tts.validator.validate()
  File "/home/roy/mycroft-core/mycroft/tts/tts.py", line 435, in validate
    self.validate_connection()
  File "/home/roy/mycroft-core/mycroft/tts/mimic_tts.py", line 189, in validate_connection
    LOG.info("Failed to find mimic at: " + BIN)
TypeError: can only concatenate str (not "NoneType") to str
2020-10-08 16:49:47.127 | ERROR    | 51541 | __main__:on_error:34 | Audio service failed to launch (TypeError('can only concatenate str (not "NoneType") to str')).

So the error message in the exception handler throws an exception making the real exception not show.

I also went through the module with pylint and fixed the issues that could be fixed without breaking backwards compatibility.

How to test

Make sure Mimic still works and unittests works. You can also set BIN to None and check that the correct exception is shown.

Contributor license agreement signed?

CLA [ Yes ]

[devops-mycroft]

Voight Kampff Integration Test Succeeded (Results)

[krisgesling]

Still a possible error. Steps to reproduce:

1. remove mimic directory
2. launch Mycroft with internet
3. disconnect internet
4. speak a request

Traceback (most recent call last):
  File "/home/gez/mycroft-core/mycroft/audio/speech.py", line 95, in handle_speak
    mute_and_speak(chunk, ident, listen)
  File "/home/gez/mycroft-core/mycroft/audio/speech.py", line 132, in mute_and_speak
    mimic_fallback_tts(utterance, ident, listen)
  File "/home/gez/mycroft-core/mycroft/audio/speech.py", line 148, in mimic_fallback_tts
    tts.execute(utterance, ident, listen)
  File "/home/gez/mycroft-core/mycroft/tts/tts.py", line 321, in execute
    self._execute(sentence, ident, listen)
  File "/home/gez/mycroft-core/mycroft/tts/tts.py", line 351, in _execute
    wav_file, phonemes = self.get_tts(sentence, wav_file)
  File "/home/gez/mycroft-core/mycroft/tts/mimic_tts.py", line 159, in get_tts
    '-t', sentence])
  File "/usr/lib/python3.6/subprocess.py", line 356, in check_output
    **kwargs).stdout
  File "/usr/lib/python3.6/subprocess.py", line 423, in run
    with Popen(*popenargs, **kwargs) as process:
  File "/usr/lib/python3.6/subprocess.py", line 729, in __init__
    restore_signals, start_new_session)
  File "/usr/lib/python3.6/subprocess.py", line 1278, in _execute_child
    executable = os.fsencode(executable)
  File "/usr/lib/python3.6/os.py", line 800, in fsencode
    filename = fspath(filename)  # Does type-checking of `filename`.
TypeError: expected str, bytes or os.PathLike object, not NoneType

Strangely in get_tts() neither sentence nor wav_file are None or NoneType values.

[forslund]

Likely the mimic path is None... The issue is that the fallback_tts object shouldn't be created at all in this case since the validation should fail (since mimic doesn't exist) will investigate

[forslund]

So the root issue seem to be that the fallback_tts was never validated. I moved things around a little and added the validation for the fallback.

[devops-mycroft]

Voight Kampff Integration Test Succeeded (Results)

[devops-mycroft]

Voight Kampff Integration Test Succeeded (Results)

[krisgesling]

Looks good, thanks Ake!