Unclear error when AudioSegment.converter is None — misleading message about file path

[VasylKolomiiets]

Problem Summary

When using AudioSegment.from_file(src_file) without explicitly setting AudioSegment.converter, the error message is vague and misleading:

expected str, bytes or os.PathLike object, not NoneType

This gives no indication that the issue is related to the internal ffmpeg subprocess, nor that AudioSegment.converter might be unset.

Why This Matters

• Developers waste hours debugging what appears to be a file path issue.
• The actual problem is the missing or misconfigured ffmpeg binary.
• Enabling DEBUG logging reveals the real cause — but this shouldn't be necessary for basic usage.

Suggested Improvement

Update the error message to include context about the subprocess:

AudioSegment.from_file() failed: subprocess parameter was None. Check if ffmpeg is installed and AudioSegment.converter is set.

Or even better, raise a custom exception with actionable advice.

Bonus

This issue was discovered only after enabling DEBUG logging. A more descriptive default error would save time and frustration for many users.

Thanks for considering!