FA-99231 / Checkpoint tensor mapping / Open access

Checkpoint mapping: tensor positions use insertion order instead of declared indices · case 01

tensor positions use insertion order instead of declared indices.

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

ROOT CAUSE

Input enumeration order is treated as the tensor position contract.

THE FAILURE

Input enumeration order is treated as the tensor position contract.

Unsuccessful approach: Sorting whole records orders by name first and can disagree with indices.

Case contract

Entries are [name,index]; return names sorted by unique consecutive indices starting at zero, else [].

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(entries):
    return [name for name,index in entries]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('reverse', solve(*([['a', 1], ['b', 0]],)), ['b', 'a'])
check('natural', solve(*([['a', 0], ['b', 1]],)), ['a', 'b'])
check('gap', solve(*([['a', 0], ['c', 2]],)), [])
check('empty', solve(*([],)), [])
check('duplicate', solve(*([['a', 0], ['b', 0]],)), [])
check('single', solve(*([['z', 0]],)), ['z'])
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
reverse	`['a', 'b']`	`['b', 'a']`	Failed
natural	`['a', 'b']`	`['a', 'b']`	Passed
gap	`['a', 'c']`	`[]`	Failed
empty	`[]`	`[]`	Passed
duplicate	`['a', 'b']`	`[]`	Failed
single	`['z']`	`['z']`	Passed

SHA-256 / 5c7892de382e0a39d3ae765378cba4d61e68a74602c40abc80b5ec2f9303046d

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(entries):
    return [name for name,index in sorted(entries)]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('reverse', solve(*([['a', 1], ['b', 0]],)), ['b', 'a'])
check('natural', solve(*([['a', 0], ['b', 1]],)), ['a', 'b'])
check('gap', solve(*([['a', 0], ['c', 2]],)), [])
check('empty', solve(*([],)), [])
check('duplicate', solve(*([['a', 0], ['b', 0]],)), [])
check('single', solve(*([['z', 0]],)), ['z'])
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
reverse	`['a', 'b']`	`['b', 'a']`	Failed
natural	`['a', 'b']`	`['a', 'b']`	Passed
gap	`['a', 'c']`	`[]`	Failed
empty	`[]`	`[]`	Passed
duplicate	`['a', 'b']`	`[]`	Failed
single	`['z']`	`['z']`	Passed

SHA-256 / adf540375391b08fe05c159dfb42978ce649c3fea4b86dbb7037f88c64e17021

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 2026-09-30T16:48:21.700749+00:00.

Case digest / be509692cf9a5d06bb13546fc697513c8065e9f66d4f2cd3ef1b8dfa9f7d22ca