Hmbown/CodeWhale · error · PersistenceBacklogError

limitations must be a non-empty string array

Error message

limitations must be a non-empty string array

What it means

Raised in validate_receipt (scripts/check-persistence-backlog-budget.py:213-217) when limitations is not a list, is empty, or contains a non-string or empty string. Every measurement receipt must carry at least one honest caveat about the measurement, so unqualified numbers cannot be presented as absolute.

Source

Thrown at scripts/check-persistence-backlog-budget.py:217

        )
    minimum_payload_bytes = retained * FIXTURE["content_bytes_per_request"]
    if receipt["estimated_retained_payload_bytes"] < minimum_payload_bytes:
        raise PersistenceBacklogError(
            "estimated_retained_payload_bytes is smaller than the frozen retained content"
        )
    applied = non_negative_integer(
        receipt["applied_version"], "applied_version"
    )
    if applied != FIXTURE["expected_applied_version"]:
        raise PersistenceBacklogError("applied_version is not the final sent version")
    if receipt["final_version_applied"] is not True:
        raise PersistenceBacklogError("final_version_applied must be true")

    limitations = receipt["limitations"]
    if not isinstance(limitations, list) or not limitations or not all(
        isinstance(item, str) and item for item in limitations
    ):
        raise PersistenceBacklogError("limitations must be a non-empty string array")

    if not isinstance(receipt["rss_supported"], bool):
        raise PersistenceBacklogError("rss_supported must be boolean")
    if receipt["rss_supported"] != (platform == "macos"):
        raise PersistenceBacklogError(
            "rss_supported must be true exactly on the macOS measurement lane"
        )
    rss_fields = RSS_SAMPLE_FIELDS + RSS_DELTA_FIELDS
    if receipt["rss_supported"]:
        for field in rss_fields:
            non_negative_integer(receipt[field], field)
        before = receipt["rss_before_bytes"]
        if receipt["rss_during_delta_bytes"] != max(
            0, receipt["rss_during_bytes"] - before
        ):
            raise PersistenceBacklogError("rss_during_delta_bytes is inconsistent")
        if receipt["rss_after_delta_bytes"] != max(
            0, receipt["rss_after_bytes"] - before

View on GitHub (pinned to 8880682c63)

Solutions

1. Restore the limitations list in the Rust measurement test with at least one meaningful string (e.g. single-sample variance, platform specificity).
2. Regenerate the receipt.
3. Keep the field non-optional in any schema refactor — the checker enforces non-emptiness.

Example fix

// receipt (before)
"limitations": []
// receipt (after)
"limitations": ["single-sample measurement; variance not captured"]

lim = receipt.get("limitations")
if not isinstance(lim, list) or not lim or not all(isinstance(s, str) and s for s in lim):
    sys.exit("limitations must be a non-empty array of non-empty strings")

def is_valid_limitations(value) -> bool:
    return isinstance(value, list) and len(value) > 0 and all(isinstance(s, str) and s for s in value)

try:
    validate_receipt(receipt)
except PersistenceBacklogError as e:
    if "limitations" in str(e):
        raise RuntimeError("receipt lacks measurement caveats; restore the emitter's limitations block") from e
    raise

When it happens

Trigger: The Rust emitter writing [] or omitting caveats; null entries; whitespace-only strings; a schema change that moved limitations elsewhere without updating the emitter.

Common situations: Emitter simplification that dropped the caveats block; receipts from an older schema where limitations was optional; hand-trimmed JSON.

Related errors

• Codewhale terminal receipt exceeded its total bound
• Codewhale stream-json line {line_number} was not an object
• invalid {label} {path}: {error}
• {label} must be a JSON object
• {field} must be a non-negative integer

AI-assisted analysis of Hmbown/CodeWhale@8880682c63 (2026-08-16). Data as JSON: /api/errors/50ce881425833fdf. Report an issue: GitHub.