What causes "baseline provenance needs an exact source SHA" in Hmbown/CodeWhale?

Record the full `git rev-parse HEAD` output (40 hex chars) as source_sha.

Hmbown/CodeWhale · error · PersistenceBacklogError

baseline provenance needs an exact source SHA

Error message

baseline provenance needs an exact source SHA

What it means

The baseline's provenance.source_sha must be a full 40-character lowercase hex git commit SHA matching SOURCE_SHA_PATTERN. This pins the baseline to an exact source revision; anything else (short SHA, dirty tag, description) is rejected.

Solutions

Record the full `git rev-parse HEAD` output (40 hex chars) as source_sha.
Regenerate the baseline with the measure script so it captures the SHA itself.
Commit the working tree first if needed, then regenerate so the recorded SHA exists.

Example fix

// before
"source_sha": "abc123"
// after
"source_sha": "0123456789abcdef0123456789abcdef01234567"

Defensive patterns

Strategy: validation

Validate before calling

import re
SHA = re.compile(r"[0-9a-f]{40}")
sha = budget.get("baseline_observation", {}).get("provenance", {}).get("source_sha", "")
if not SHA.fullmatch(sha):
    raise ValueError("source_sha must be a full 40-char hex SHA")

Type guard

def has_full_sha(p: dict) -> bool:
    return bool(re.fullmatch(r"[0-9a-f]{40}", p.get("source_sha", "")))

Try / catch

try:
    compare(budget, baseline_receipt)
except PersistenceBacklogError as e:
    if "exact source SHA" in str(e): re-record `git rev-parse HEAD` and regenerate

Prevention

Always use `git rev-parse HEAD`, never abbreviated hashes.
Generate baselines from committed, non-shallow clones.

When it happens

Trigger: `compare` with provenance.source_sha that is missing, non-string, a short/abbreviated SHA, or contains uppercase or non-hex characters.

Common situations: Hand-written source_sha, a baseline generated from a shallow/partial clone producing an abbreviated hash, or an old baseline from a different repository state.

Understand the failure class

Background: "invalid id" errors: invalid identifier format — why libraries reject IDs before lookup, and how to fix them — this error's family across 37 libraries.

Related errors

AI-assisted analysis of Hmbown/CodeWhale@433685b202 (2026-09-15). Data as JSON: /api/errors/ad2ee2bac2c8ec23. Report an issue: GitHub.

Appendix: source

Thrown at scripts/check-persistence-backlog-budget.py:306

            "baseline_observation must retain the final request and payload"
        )
    if baseline_retained > baseline_accepted:
        raise PersistenceBacklogError(
            "baseline_observation.retained_queued_requests exceeds accepted_requests"
        )
    if baseline_payload < baseline_retained * FIXTURE["content_bytes_per_request"]:
        raise PersistenceBacklogError(
            "baseline_observation payload is smaller than frozen retained content"
        )
    provenance = baseline.get("provenance")
    if not isinstance(provenance, dict):
        raise PersistenceBacklogError("baseline_observation needs provenance")
    if provenance.get("platform") != "macos":
        raise PersistenceBacklogError("baseline provenance platform must be macos")
    if not isinstance(provenance.get("source_sha"), str) or not SOURCE_SHA_PATTERN.fullmatch(
        provenance["source_sha"]
    ):
        raise PersistenceBacklogError("baseline provenance needs an exact source SHA")
    if provenance.get("source_dirty") is not False:
        raise PersistenceBacklogError("baseline provenance must identify a clean source tree")
    for field, prefix in (("rustc_version", "rustc "), ("cargo_version", "cargo ")):
        if not isinstance(provenance.get(field), str) or not provenance[field].startswith(prefix):
            raise PersistenceBacklogError(f"baseline provenance needs {field}")
    if provenance.get("build_profile") != "test" or not (
        type(provenance.get("sample_count")) is int
        and provenance["sample_count"] == 1
    ):
        raise PersistenceBacklogError("baseline provenance build profile/sample count changed")


def validate_baseline_receipt(
    budget: dict[str, Any], baseline_receipt: dict[str, Any]
) -> None:
    validate_receipt(baseline_receipt, require_clean_source=True)
    baseline = budget["baseline_observation"]
    for field in ("accepted_requests", "applied_version", *CEILING_FIELDS):

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