FA-10371 / Observability / Open access

Trace export admission: Nonroot spans export without required parent linkage · case 01

Nonroot spans export without required parent linkage.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The implementation substitutes True for (span['root'] or span['parent'] is not None), so nonroot spans export without required parent linkage.

THE FAILURE

The implementation substitutes True for (span['root'] or span['parent'] is not None), so nonroot spans export without required parent linkage.

Unsuccessful approach: The attempted repair substitutes bool(span['parent']). Fixture 1 still yields False instead of True.

Case contract

Export ended sampled spans that are not locally suppressed, have valid parent linkage when a parent is required, and carry the required service identity. Root spans need no parent.

Why this case matters

An offline model of trace export admission, suitable for testing build and release tooling without external services.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(span):
    return span['ended'] and span['sampled'] and not span['suppressed'] and True and bool(span['service'])
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve({'ended': True, 'sampled': True, 'suppressed': False, 'root': True, 'parent': None, 'service': 'api'}), True)
check('fixture 2', solve({'ended': False, 'sampled': True, 'suppressed': False, 'root': True, 'parent': None, 'service': 'api'}), False)
check('fixture 3', solve({'ended': True, 'sampled': False, 'suppressed': False, 'root': True, 'parent': None, 'service': 'api'}), False)
check('fixture 4', solve({'ended': True, 'sampled': True, 'suppressed': True, 'root': True, 'parent': None, 'service': 'api'}), False)
check('fixture 5', solve({'ended': True, 'sampled': True, 'suppressed': False, 'root': False, 'parent': None, 'service': 'api'}), False)
check('fixture 6', solve({'ended': True, 'sampled': True, 'suppressed': False, 'root': False, 'parent': 'p', 'service': 'api'}), True)
check('fixture 7', solve({'ended': True, 'sampled': True, 'suppressed': False, 'root': True, 'parent': None, 'service': ''}), False)
check('fixture 8', solve({'ended': True, 'sampled': True, 'suppressed': False, 'root': False, 'parent': '', 'service': 'api'}), True)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
fixture 1	`True`	`True`	Passed
fixture 2	`False`	`False`	Passed
fixture 3	`False`	`False`	Passed
fixture 4	`False`	`False`	Passed
fixture 5	`True`	`False`	Failed
fixture 6	`True`	`True`	Passed
fixture 7	`False`	`False`	Passed
fixture 8	`True`	`True`	Passed

SHA-256 / 271c3d3332901df8c11740f676011590654ec9a138e4e7c8fd415aab76100466

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(span):
    return span['ended'] and span['sampled'] and not span['suppressed'] and bool(span['parent']) and bool(span['service'])
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve({'ended': True, 'sampled': True, 'suppressed': False, 'root': True, 'parent': None, 'service': 'api'}), True)
check('fixture 2', solve({'ended': False, 'sampled': True, 'suppressed': False, 'root': True, 'parent': None, 'service': 'api'}), False)
check('fixture 3', solve({'ended': True, 'sampled': False, 'suppressed': False, 'root': True, 'parent': None, 'service': 'api'}), False)
check('fixture 4', solve({'ended': True, 'sampled': True, 'suppressed': True, 'root': True, 'parent': None, 'service': 'api'}), False)
check('fixture 5', solve({'ended': True, 'sampled': True, 'suppressed': False, 'root': False, 'parent': None, 'service': 'api'}), False)
check('fixture 6', solve({'ended': True, 'sampled': True, 'suppressed': False, 'root': False, 'parent': 'p', 'service': 'api'}), True)
check('fixture 7', solve({'ended': True, 'sampled': True, 'suppressed': False, 'root': True, 'parent': None, 'service': ''}), False)
check('fixture 8', solve({'ended': True, 'sampled': True, 'suppressed': False, 'root': False, 'parent': '', 'service': 'api'}), True)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
fixture 1	`False`	`True`	Failed
fixture 2	`False`	`False`	Passed
fixture 3	`False`	`False`	Passed
fixture 4	`False`	`False`	Passed
fixture 5	`False`	`False`	Passed
fixture 6	`True`	`True`	Passed
fixture 7	`False`	`False`	Passed
fixture 8	`False`	`True`	Failed

SHA-256 / 9ece6d87cd9e47266e7c24519cb3e5966411a2bece7477a952532a121b0784a5

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 8 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

Member access is invitation-based. Sign in with your invited account to inspect the repair.

Verification & scope

This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:38:38.469618+00:00.

Case digest / bb3191b83a2121725271258188c07b9ab7af39bf4cd07c4db5c8553509eaf3c9