determined that purpose of config file is: train
will add 'csv_path' option to 'TRAIN' section
purpose for dataset: train
will split dataset
making array files containing spectrograms from audio files in: /Users/Lab/VAK_test/test
/Users/Lab/VAK_test/test/01-F81AD-191209_1807_halfhr1_callsegs_st_53989425-54099675
01-F81AD-191209_1807_halfhr1_callsegs_st_53989425-54099675

Traceback (most recent call last):
  File "/Users/Lab/anaconda3/envs/vak-env/bin/vak", line 10, in <module>
    sys.exit(main())
  File "/Users/Lab/anaconda3/envs/vak-env/lib/python3.9/site-packages/vak/__main__.py", line 45, in main
    cli.cli(command=args.command, config_file=args.configfile)
  File "/Users/Lab/anaconda3/envs/vak-env/lib/python3.9/site-packages/vak/cli/cli.py", line 30, in cli
    COMMAND_FUNCTION_MAP[command](toml_path=config_file)
  File "/Users/Lab/anaconda3/envs/vak-env/lib/python3.9/site-packages/vak/cli/prep.py", line 132, in prep
    vak_df, csv_path = core.prep(
  File "/Users/Lab/anaconda3/envs/vak-env/lib/python3.9/site-packages/vak/core/prep.py", line 205, in prep
    vak_df = dataframe.from_files(
  File "/Users/Lab/anaconda3/envs/vak-env/lib/python3.9/site-packages/vak/io/dataframe.py", line 137, in from_files
    spect_files = audio.to_spect(
  File "/Users/Lab/anaconda3/envs/vak-env/lib/python3.9/site-packages/vak/io/audio.py", line 174, in to_spect
    audio_annot_map = source_annot_map(audio_files, annot_list)
  File "/Users/Lab/anaconda3/envs/vak-env/lib/python3.9/site-packages/vak/annotation.py", line 210, in source_annot_map
    keys = [recursive_stem(annot.audio_path) for annot in annot_list]
  File "/Users/Lab/anaconda3/envs/vak-env/lib/python3.9/site-packages/vak/annotation.py", line 210, in <listcomp>
    keys = [recursive_stem(annot.audio_path) for annot in annot_list]
  File "/Users/Lab/anaconda3/envs/vak-env/lib/python3.9/site-packages/vak/annotation.py", line 175, in recursive_stem
    raise ValueError(f"unable to compute stem of {path}")
ValueError: unable to compute stem of /Users/Lab/VAK_test/test/01-F81AD-191209_1807_halfhr1_callsegs_st_53989425-54099675