FA-99211 / Checkpoint tensor mapping / Open access

Checkpoint mapping: interior marker occurrence is mistaken for shadow suffix · case 01

interior marker occurrence is mistaken for shadow suffix.

Verified by executionVariant 1 · 6 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Any occurrence is mistaken for a terminal shadow marker.

THE FAILURE

Any occurrence is mistaken for a terminal shadow marker.

Unsuccessful approach: Checking only the characters ema also accepts names without the marker separator.

Case contract

Select names that end exactly with ".ema" and strip that suffix.

Why this case matters

A bounded offline model of checkpoint tensor bookkeeping in a training workflow.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(names):
    return sorted(n.replace(".ema", "") for n in names if ".ema" in n)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('interior', solve(*(['layer.ema.weight'],)), [])
check('suffix', solve(*(['layer3.ema'],)), ['layer3'])
check('plain', solve(*(['layer.weight'],)), [])
check('empty', solve(*([],)), [])
check('exact marker', solve(*(['.ema'],)), [''])
check('bare suffix chars', solve(*(['layerema'],)), [])
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
interior	`['layer.weight']`	`[]`	Failed
suffix	`['layer3']`	`['layer3']`	Passed
plain	`[]`	`[]`	Passed
empty	`[]`	`[]`	Passed
exact marker	`['']`	`['']`	Passed
bare suffix chars	`[]`	`[]`	Passed

SHA-256 / 291940caea902edc9234ddf118fcf21347464479b30d63d41096e9ee222e7eb6

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(names):
    return sorted(n[:n.find(".ema")] for n in names if n.endswith("ema"))
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('interior', solve(*(['layer.ema.weight'],)), [])
check('suffix', solve(*(['layer3.ema'],)), ['layer3'])
check('plain', solve(*(['layer.weight'],)), [])
check('empty', solve(*([],)), [])
check('exact marker', solve(*(['.ema'],)), [''])
check('bare suffix chars', solve(*(['layerema'],)), [])
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
interior	`[]`	`[]`	Passed
suffix	`['layer3']`	`['layer3']`	Passed
plain	`[]`	`[]`	Passed
empty	`[]`	`[]`	Passed
exact marker	`['']`	`['']`	Passed
bare suffix chars	`['layerem']`	`[]`	Failed

SHA-256 / ba1f7264221c7769fb2e9f65cc2f4408e230494a52a11e942aa7d1b79ea21c54

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 6 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

Inputs are already decoded Python values; this toy contract makes no claim about a framework, file format, or production checkpoint. 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 2026-09-30T16:48:21.699305+00:00.

Case digest / 7f6bc113f264fe69b0349d4eeefc36ab79a5d5dea1b2c39dbfdb89df2fb06dc9