IndexError to examine

[malcolmsailor]

Following (random) settings give an IndexError:

{
    "seed": 3983367668,
    "num_voices": 2,
    "pattern_len": (4, 7),
    "rhythm_len": (4, 7),
    "pitch_loop": False,
    "harmony_len": (4, 7),
    "truncate_patterns": False,
    "voice_order_str": "reverse",
    "interval_cycle": (11),
    "chords": (
        (1.0, 1.25, 1.5),
        (1.66667, 2.0, 2.5),
        (1.125, 1.35, 1.6875),
        (1.125, 1.35, 1.6875),
    ),
    "parallel_voice_leading": False,
    "voice_lead_chord_tones": True,
    "preserve_foot_in_bass": "none",
    "chord_tone_and_foot_disable": False,
    "chord_tone_selection": False,
    "force_chord_tone": "none",
    "chord_tones_sync_onset_in_all_voices": False,
    "force_foot_in_bass": "first_note",
    "prefer_small_melodic_intervals": True,
    "force_repeated_notes": False,
    "force_parallel_motion": False,
    "consonance_treatment": "all_onsets",
    "cont_rhythms": "none",
    "vary_rhythm_consistently": False,
    "rhythmic_unison": True,
    "rhythmic_quasi_unison": True,
    "hocketing": True,
    "onset_density": (0.3, 0.95),
    "dur_density": (0.1, 0.2),
    "onset_subdivision": 0.16666666666666666,
    "randomly_distribute_between_choirs": True,
    "length_choir_segments": 0.25,
    "tempo": 159,
}

Traceback:

Traceback (most recent call last):
  File "/opt/homebrew/Cellar/python@3.9/3.9.16/Frameworks/Python.framework/Versions/3.9/lib/python3.9/runpy.py", line 197, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/opt/homebrew/Cellar/python@3.9/3.9.16/Frameworks/Python.framework/Versions/3.9/lib/python3.9/runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "/Users/malcolm/google_drive/python/efficient_rhythms/efficient_rhythms/__main__.py", line 165, in <module>
    main()
  File "/Users/malcolm/google_drive/python/efficient_rhythms/efficient_rhythms/__main__.py", line 150, in main
    settings, changers, pattern, changed_pattern = build(args)
  File "/Users/malcolm/google_drive/python/efficient_rhythms/efficient_rhythms/__main__.py", line 100, in build
    pattern = make_pattern(args, settings)
  File "/Users/malcolm/google_drive/python/efficient_rhythms/efficient_rhythms/__main__.py", line 85, in make_pattern
    pattern = er_make_handler.make_super_pattern(settings)
  File "/Users/malcolm/google_drive/python/efficient_rhythms/efficient_rhythms/er_make_handler.py", line 82, in make_super_pattern
    raise main_thread.exc
  File "/Users/malcolm/google_drive/python/efficient_rhythms/efficient_rhythms/er_make_handler.py", line 59, in function
    self.result = target(*args, **kwargs)
  File "/Users/malcolm/google_drive/python/efficient_rhythms/efficient_rhythms/er_make.py", line 999, in make_super_pattern
    if voice_lead_pattern(er, super_pattern, voice_lead_error):
  File "/Users/malcolm/google_drive/python/efficient_rhythms/efficient_rhythms/er_make.py", line 972, in voice_lead_pattern
    and er_vl_strict_and_flex.voice_lead_pattern_strictly(
  File "/Users/malcolm/google_drive/python/efficient_rhythms/efficient_rhythms/er_vl_strict_and_flex.py", line 267, in voice_lead_pattern_strictly
    if voice_lead_pattern_strictly(
  File "/Users/malcolm/google_drive/python/efficient_rhythms/efficient_rhythms/er_vl_strict_and_flex.py", line 261, in voice_lead_pattern_strictly
    new_notes = strict_voice_leading_loop(
  File "/Users/malcolm/google_drive/python/efficient_rhythms/efficient_rhythms/er_vl_strict_and_flex.py", line 168, in strict_voice_leading_loop
    prev_note = voice.get_notes_by_i(prev_note_j)[0]
  File "/Users/malcolm/google_drive/python/efficient_rhythms/efficient_rhythms/er_classes/voice.py", line 202, in get_notes_by_i
    return self._data.peekitem(i)[1]
  File "/Users/malcolm/venvs/efficient_rhythms/lib/python3.9/site-packages/sortedcontainers/sorteddict.py", line 510, in peekitem
    key = self._list[index]
  File "/Users/malcolm/venvs/efficient_rhythms/lib/python3.9/site-packages/sortedcontainers/sortedlist.py", line 901, in __getitem__
    pos, idx = self._pos(index)
  File "/Users/malcolm/venvs/efficient_rhythms/lib/python3.9/site-packages/sortedcontainers/sortedlist.py", line 667, in _pos
    raise IndexError('list index out of range')
IndexError: list index out of range