Adversarial retest (Lena), 2026-10-20 UTC+8, repo 34f5195, with pydub + audioop-lts installed (the docs' requirement for MP3/FLAC/OGG).

== repo/audacity/agent-harness/cli_anything/audacity/core/export.py lines 196-212 ==
    else:
        # Empty project: generate 1 second of silence
        mixed = generate_silence(1.0, sample_rate, out_channels)

    # Clamp to prevent clipping
    mixed = clamp_samples(mixed)

    # Export
    if fmt == "WAV":
        write_wav(output_path, mixed, sample_rate, out_channels, bit_depth)
    else:
        # For non-WAV formats, write a WAV first and note that conversion
        # requires external tools
        write_wav(output_path, mixed, sample_rate, out_channels, bit_depth)

    # Verify output
    file_size = os.path.getsize(output_path)

== grep pydub in the audacity package (only description strings, no import) ==
repo/audacity/agent-harness/cli_anything/audacity/core/export.py:69:        "description": "MP3 (requires pydub/ffmpeg)",
repo/audacity/agent-harness/cli_anything/audacity/core/export.py:75:        "description": "FLAC lossless (requires pydub/ffmpeg)",
repo/audacity/agent-harness/cli_anything/audacity/core/export.py:81:        "description": "OGG Vorbis (requires pydub/ffmpeg)",
repo/audacity/agent-harness/cli_anything/audacity/core/export.py:87:        "description": "AIFF (requires pydub/ffmpeg)",

== outputs: md5 and file type ==
1c4267428d15ab5c360855ffa0e35495  out.aiff
1c4267428d15ab5c360855ffa0e35495  out.flac
1c4267428d15ab5c360855ffa0e35495  out.mp3
1c4267428d15ab5c360855ffa0e35495  out.ogg
1c4267428d15ab5c360855ffa0e35495  out.wav
out.aiff: RIFF (little-endian) data, WAVE audio, Microsoft PCM, 16 bit, mono 44100 Hz
out.flac: RIFF (little-endian) data, WAVE audio, Microsoft PCM, 16 bit, mono 44100 Hz
out.mp3:  RIFF (little-endian) data, WAVE audio, Microsoft PCM, 16 bit, mono 44100 Hz
out.ogg:  RIFF (little-endian) data, WAVE audio, Microsoft PCM, 16 bit, mono 44100 Hz
out.wav:  RIFF (little-endian) data, WAVE audio, Microsoft PCM, 16 bit, mono 44100 Hz

== json-mp3.txt ==
{
  "output": "/workspace/retest-cli-anything/taskB/out.mp3",
  "format": "MP3",
  "sample_rate": 44100,
  "channels": 1,
  "bit_depth": 16,
  "duration": 3.0,
  "duration_human": "00:03.000",
  "file_size": 264644,
  "file_size_human": "258.4 KB",
  "preset": "mp3",
  "tracks_rendered": 1,
  "peak_level": 0.5,
  "rms_level": 0.3535
}

== strace-mp3.txt (execve only: no sox, no audacity) ==
348296 execve("/workspace/retest-cli-anything/venv/bin/cli-anything-audacity", ["cli-anything-audacity", "--json", "--project", "t.json", "export", "render", "out.mp3", "-p", "mp3", "--overwrite"], 0x7ffd9f1cec78 /* 64 vars */) = 0
== json-flac.txt ==
{
  "output": "/workspace/retest-cli-anything/taskB/out.flac",
  "format": "FLAC",
  "sample_rate": 44100,
  "channels": 1,
  "bit_depth": 16,
  "duration": 3.0,
  "duration_human": "00:03.000",
  "file_size": 264644,
  "file_size_human": "258.4 KB",
  "preset": "flac",
  "tracks_rendered": 1,
  "peak_level": 0.5,
  "rms_level": 0.3535
}

== strace-flac.txt (execve only: no sox, no audacity) ==
348305 execve("/workspace/retest-cli-anything/venv/bin/cli-anything-audacity", ["cli-anything-audacity", "--json", "--project", "t.json", "export", "render", "out.flac", "-p", "flac", "--overwrite"], 0x7ffdf33aa7d8 /* 64 vars */) = 0
== json-ogg.txt ==
{
  "output": "/workspace/retest-cli-anything/taskB/out.ogg",
  "format": "OGG",
  "sample_rate": 44100,
  "channels": 1,
  "bit_depth": 16,
  "duration": 3.0,
  "duration_human": "00:03.000",
  "file_size": 264644,
  "file_size_human": "258.4 KB",
  "preset": "ogg",
  "tracks_rendered": 1,
  "peak_level": 0.5,
  "rms_level": 0.3535
}

== strace-ogg.txt (execve only: no sox, no audacity) ==
348314 execve("/workspace/retest-cli-anything/venv/bin/cli-anything-audacity", ["cli-anything-audacity", "--json", "--project", "t.json", "export", "render", "out.ogg", "-p", "ogg", "--overwrite"], 0x7fff4d96e588 /* 64 vars */) = 0
== strace-fx.txt (export with echo, change_pitch, low_pass) ==
348936 execve("/workspace/retest-cli-anything/venv/bin/cli-anything-audacity", ["cli-anything-audacity", "--json", "--project", "e.json", "export", "render", "fx.wav", "-p", "wav", "--overwrite"], 0x7ffcbdd0fb38 /* 64 vars */) = 0