FA-99206 / Checkpoint tensor mapping / Open access

Checkpoint mapping: slot suffix matching associates the wrong parameter · case 01

slot suffix matching associates the wrong parameter.

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

ROOT CAUSE

Substring matching associates unrelated parameter names with a slot.

THE FAILURE

Substring matching associates unrelated parameter names with a slot.

Unsuccessful approach: A suffix check accepts longer prefixes that happen to end with the parameter name.

Case contract

Return sorted [parameter,slot] pairs where slot name is exactly parameter + ".moment" and parameter exists.

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(parameters, slots):
    return sorted([p,s] for p in parameters for s in slots if p in s)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('substring', solve(*(['a'], ['xa.moment'])), [])
check('exact', solve(*(['a'], ['a.moment'])), [['a', 'a.moment']])
check('prefix collision', solve(*(['a', 'ab'], ['ab.moment'])), [['ab', 'ab.moment']])
check('empty', solve(*([], ['a.moment'])), [])
check('no slot', solve(*(['a'], [])), [])
check('many', solve(*(['w3', 'b'], ['w3.moment', 'b.moment'])), [['b', 'b.moment'], ['w3', 'w3.moment']])
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
substring	`[['a', 'xa.moment']]`	`[]`	Failed
exact	`[['a', 'a.moment']]`	`[['a', 'a.moment']]`	Passed
prefix collision	`[['a', 'ab.moment'], ['ab', 'ab.moment']]`	`[['ab', 'ab.moment']]`	Failed
empty	`[]`	`[]`	Passed
no slot	`[]`	`[]`	Passed
many	`[['b', 'b.moment'], ['w3', 'w3.moment']]`	`[['b', 'b.moment'], ['w3', 'w3.moment']]`	Passed

SHA-256 / c5229ad24636c18d8f1f740932dfb1acf433a4f01fae024c0d5d41b632778ed4

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(parameters, slots):
    return sorted([p,s] for p in parameters for s in slots if s.endswith(p+".moment"))
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('substring', solve(*(['a'], ['xa.moment'])), [])
check('exact', solve(*(['a'], ['a.moment'])), [['a', 'a.moment']])
check('prefix collision', solve(*(['a', 'ab'], ['ab.moment'])), [['ab', 'ab.moment']])
check('empty', solve(*([], ['a.moment'])), [])
check('no slot', solve(*(['a'], [])), [])
check('many', solve(*(['w3', 'b'], ['w3.moment', 'b.moment'])), [['b', 'b.moment'], ['w3', 'w3.moment']])
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
substring	`[['a', 'xa.moment']]`	`[]`	Failed
exact	`[['a', 'a.moment']]`	`[['a', 'a.moment']]`	Passed
prefix collision	`[['ab', 'ab.moment']]`	`[['ab', 'ab.moment']]`	Passed
empty	`[]`	`[]`	Passed
no slot	`[]`	`[]`	Passed
many	`[['b', 'b.moment'], ['w3', 'w3.moment']]`	`[['b', 'b.moment'], ['w3', 'w3.moment']]`	Passed

SHA-256 / 68ed9c31e487f10bd80d8c843f4662605a97c99417e8f1c7773f6c00bc7b4ebf

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 2026-09-30T16:48:21.700260+00:00.

Case digest / 9ba6081395bce906759dea1f3c98ff8f90506f093d356c6974fbe324e1fc6952