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FA-44246 / Borrow checking / Open access

Borrow proof cache keys only the owner root and confuses sibling projections · case 01

Borrow proof cache keys only the owner root and confuses sibling projections.

Verified by executionVariant 1 · 21 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The static analyzer mishandles normalized place key: borrow proof cache keys only the owner root and confuses sibling projections.

THE FAILURE

The static analyzer mishandles normalized place key: borrow proof cache keys only the owner root and confuses sibling projections.

Unsuccessful approach: The partial repair uses if d['reused'] and d['cached_place'][:1]!=d['place'][:1]: errors.append('normalized-place-key'), which still violates the stipulated analysis contract.

Case contract

Validate reuse of static borrow proof certificates. Cache entry belongs to same IR revision, same normalized place, same mutability, same lifetime substitution, same solver universe, same CFG edge kind and same target layout; negative results are invalidated when new outlives facts arrive; incomplete fixed-point results are never reusable; diagnostic reuse rebinds source spans to current lifetime occurrence mapping. Input is a fully explicit descriptor of the stated toy IR. Return rule identifiers in declaration order; absent optional obligations use the provided neutral defaults. No rule is an assertion about a production language.

Why this case matters

A finite offline static-analysis model of ownership and borrowing; it does not execute the analyzed program.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(d):
    errors=[]
    if d['reused'] and d['cached_revision']!=d['revision']: errors.append('ir-revision')
    if False: errors.append('normalized-place-key')
    if d['reused'] and d['cached_mut']!=d['mutable']: errors.append('permission-key')
    if d['reused'] and d['cached_substitution']!=d['substitution']: errors.append('substitution-key')
    if d['reused'] and d['cached_universe']!=d['universe']: errors.append('universe-key')
    if d['reused'] and d['cached_edge']!=d['edge']: errors.append('edge-kind-key')
    if d['reused'] and d['cached_layout']!=d['layout']: errors.append('layout-key')
    if d['reused'] and d['negative'] and set(d['old_facts'])!=set(d['facts']): errors.append('negative-fact-invalidation')
    if d['reused'] and not d['complete']: errors.append('provisional-result')
    if d['reused'] and d['cached_spans']!=d['spans']: errors.append('diagnostic-span-rebind')
    return errors
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
base={'cached_revision': 0, 'revision': 0, 'cached_place': [], 'place': [], 'cached_mut': False, 'mutable': False, 'cached_substitution': {}, 'substitution': {}, 'cached_universe': 0, 'universe': 0, 'cached_edge': 'normal', 'edge': 'normal', 'cached_layout': [], 'layout': [], 'negative': False, 'old_facts': [], 'facts': [], 'complete': True, 'reused': False, 'cached_spans': {}, 'spans': {}}
check('well formed empty obligations',solve(base),[])
check('ir-revision regression 0', solve(dict(base, **({'reused':True,'cached_revision':N,'revision':N+1}))), ['ir-revision'])
check('ir-revision regression 1', solve(dict(base, **({'reused':True,'cached_revision':N+1,'revision':N+2}))), ['ir-revision'])
check('normalized-place-key regression 0', solve(dict(base, **({'reused':True,'cached_place':['r','a'],'place':['r','b']}))), ['normalized-place-key'])
check('normalized-place-key regression 1', solve(dict(base, **({'reused':True,'cached_place':['r',N],'place':['r',N+1]}))), ['normalized-place-key'])
check('permission-key regression 0', solve(dict(base, **({'reused':True,'cached_mut':False,'mutable':True}))), ['permission-key'])
check('permission-key regression 1', solve(dict(base, **({'reused':True,'cached_mut':False,'mutable':True,'revision':N,'cached_revision':N}))), ['permission-key'])
check('substitution-key regression 0', solve(dict(base, **({'reused':True,'cached_substitution':{'a':'x'},'substitution':{'a':'y'}}))), ['substitution-key'])
check('substitution-key regression 1', solve(dict(base, **({'reused':True,'cached_substitution':{'a':N},'substitution':{'a':N+1}}))), ['substitution-key'])
check('universe-key regression 0', solve(dict(base, **({'reused':True,'cached_universe':N,'universe':N+1}))), ['universe-key'])
check('universe-key regression 1', solve(dict(base, **({'reused':True,'cached_universe':N+1,'universe':N+2}))), ['universe-key'])
check('edge-kind-key regression 0', solve(dict(base, **({'reused':True,'cached_edge':'normal','edge':'unwind'}))), ['edge-kind-key'])
check('edge-kind-key regression 1', solve(dict(base, **({'reused':True,'cached_edge':'normal','edge':'cancel','revision':N,'cached_revision':N}))), ['edge-kind-key'])
check('layout-key regression 0', solve(dict(base, **({'reused':True,'cached_layout':[0,4],'layout':[0,8]}))), ['layout-key'])
check('layout-key regression 1', solve(dict(base, **({'reused':True,'cached_layout':[0,N],'layout':[0,N+1]}))), ['layout-key'])
check('negative-fact-invalidation regression 0', solve(dict(base, **({'reused':True,'negative':True,'old_facts':['a'],'facts':['a','b']}))), ['negative-fact-invalidation'])
check('negative-fact-invalidation regression 1', solve(dict(base, **({'reused':True,'negative':True,'old_facts':[N],'facts':[N,N+1]}))), ['negative-fact-invalidation'])
check('provisional-result regression 0', solve(dict(base, **({'reused':True,'complete':False}))), ['provisional-result'])
check('provisional-result regression 1', solve(dict(base, **({'reused':True,'complete':False,'revision':N,'cached_revision':N}))), ['provisional-result'])
check('diagnostic-span-rebind regression 0', solve(dict(base, **({'reused':True,'cached_spans':{'a':1},'spans':{'a':2}}))), ['diagnostic-span-rebind'])
check('diagnostic-span-rebind regression 1', solve(dict(base, **({'reused':True,'cached_spans':{'a':N},'spans':{'a':N+1}}))), ['diagnostic-span-rebind'])
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 fixtureActualExpectedOutcome
well formed empty obligations[][]Passed
ir-revision regression 0['ir-revision']['ir-revision']Passed
ir-revision regression 1['ir-revision']['ir-revision']Passed
normalized-place-key regression 0[]['normalized-place-key']Failed
normalized-place-key regression 1[]['normalized-place-key']Failed
permission-key regression 0['permission-key']['permission-key']Passed
permission-key regression 1['permission-key']['permission-key']Passed
substitution-key regression 0['substitution-key']['substitution-key']Passed
substitution-key regression 1['substitution-key']['substitution-key']Passed
universe-key regression 0['universe-key']['universe-key']Passed
universe-key regression 1['universe-key']['universe-key']Passed
edge-kind-key regression 0['edge-kind-key']['edge-kind-key']Passed
edge-kind-key regression 1['edge-kind-key']['edge-kind-key']Passed
layout-key regression 0['layout-key']['layout-key']Passed
layout-key regression 1['layout-key']['layout-key']Passed
negative-fact-invalidation regression 0['negative-fact-invalidation']['negative-fact-invalidation']Passed
negative-fact-invalidation regression 1['negative-fact-invalidation']['negative-fact-invalidation']Passed
provisional-result regression 0['provisional-result']['provisional-result']Passed
provisional-result regression 1['provisional-result']['provisional-result']Passed
diagnostic-span-rebind regression 0['diagnostic-span-rebind']['diagnostic-span-rebind']Passed
diagnostic-span-rebind regression 1['diagnostic-span-rebind']['diagnostic-span-rebind']Passed

SHA-256 / 86eff5eaeb60834e7ee4784f10b0b1e0c463434debb5455b0d68059e20ff76f2

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(d):
    errors=[]
    if d['reused'] and d['cached_revision']!=d['revision']: errors.append('ir-revision')
    if d['reused'] and d['cached_place'][:1]!=d['place'][:1]: errors.append('normalized-place-key')
    if d['reused'] and d['cached_mut']!=d['mutable']: errors.append('permission-key')
    if d['reused'] and d['cached_substitution']!=d['substitution']: errors.append('substitution-key')
    if d['reused'] and d['cached_universe']!=d['universe']: errors.append('universe-key')
    if d['reused'] and d['cached_edge']!=d['edge']: errors.append('edge-kind-key')
    if d['reused'] and d['cached_layout']!=d['layout']: errors.append('layout-key')
    if d['reused'] and d['negative'] and set(d['old_facts'])!=set(d['facts']): errors.append('negative-fact-invalidation')
    if d['reused'] and not d['complete']: errors.append('provisional-result')
    if d['reused'] and d['cached_spans']!=d['spans']: errors.append('diagnostic-span-rebind')
    return errors
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
base={'cached_revision': 0, 'revision': 0, 'cached_place': [], 'place': [], 'cached_mut': False, 'mutable': False, 'cached_substitution': {}, 'substitution': {}, 'cached_universe': 0, 'universe': 0, 'cached_edge': 'normal', 'edge': 'normal', 'cached_layout': [], 'layout': [], 'negative': False, 'old_facts': [], 'facts': [], 'complete': True, 'reused': False, 'cached_spans': {}, 'spans': {}}
check('well formed empty obligations',solve(base),[])
check('ir-revision regression 0', solve(dict(base, **({'reused':True,'cached_revision':N,'revision':N+1}))), ['ir-revision'])
check('ir-revision regression 1', solve(dict(base, **({'reused':True,'cached_revision':N+1,'revision':N+2}))), ['ir-revision'])
check('normalized-place-key regression 0', solve(dict(base, **({'reused':True,'cached_place':['r','a'],'place':['r','b']}))), ['normalized-place-key'])
check('normalized-place-key regression 1', solve(dict(base, **({'reused':True,'cached_place':['r',N],'place':['r',N+1]}))), ['normalized-place-key'])
check('permission-key regression 0', solve(dict(base, **({'reused':True,'cached_mut':False,'mutable':True}))), ['permission-key'])
check('permission-key regression 1', solve(dict(base, **({'reused':True,'cached_mut':False,'mutable':True,'revision':N,'cached_revision':N}))), ['permission-key'])
check('substitution-key regression 0', solve(dict(base, **({'reused':True,'cached_substitution':{'a':'x'},'substitution':{'a':'y'}}))), ['substitution-key'])
check('substitution-key regression 1', solve(dict(base, **({'reused':True,'cached_substitution':{'a':N},'substitution':{'a':N+1}}))), ['substitution-key'])
check('universe-key regression 0', solve(dict(base, **({'reused':True,'cached_universe':N,'universe':N+1}))), ['universe-key'])
check('universe-key regression 1', solve(dict(base, **({'reused':True,'cached_universe':N+1,'universe':N+2}))), ['universe-key'])
check('edge-kind-key regression 0', solve(dict(base, **({'reused':True,'cached_edge':'normal','edge':'unwind'}))), ['edge-kind-key'])
check('edge-kind-key regression 1', solve(dict(base, **({'reused':True,'cached_edge':'normal','edge':'cancel','revision':N,'cached_revision':N}))), ['edge-kind-key'])
check('layout-key regression 0', solve(dict(base, **({'reused':True,'cached_layout':[0,4],'layout':[0,8]}))), ['layout-key'])
check('layout-key regression 1', solve(dict(base, **({'reused':True,'cached_layout':[0,N],'layout':[0,N+1]}))), ['layout-key'])
check('negative-fact-invalidation regression 0', solve(dict(base, **({'reused':True,'negative':True,'old_facts':['a'],'facts':['a','b']}))), ['negative-fact-invalidation'])
check('negative-fact-invalidation regression 1', solve(dict(base, **({'reused':True,'negative':True,'old_facts':[N],'facts':[N,N+1]}))), ['negative-fact-invalidation'])
check('provisional-result regression 0', solve(dict(base, **({'reused':True,'complete':False}))), ['provisional-result'])
check('provisional-result regression 1', solve(dict(base, **({'reused':True,'complete':False,'revision':N,'cached_revision':N}))), ['provisional-result'])
check('diagnostic-span-rebind regression 0', solve(dict(base, **({'reused':True,'cached_spans':{'a':1},'spans':{'a':2}}))), ['diagnostic-span-rebind'])
check('diagnostic-span-rebind regression 1', solve(dict(base, **({'reused':True,'cached_spans':{'a':N},'spans':{'a':N+1}}))), ['diagnostic-span-rebind'])
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 fixtureActualExpectedOutcome
well formed empty obligations[][]Passed
ir-revision regression 0['ir-revision']['ir-revision']Passed
ir-revision regression 1['ir-revision']['ir-revision']Passed
normalized-place-key regression 0[]['normalized-place-key']Failed
normalized-place-key regression 1[]['normalized-place-key']Failed
permission-key regression 0['permission-key']['permission-key']Passed
permission-key regression 1['permission-key']['permission-key']Passed
substitution-key regression 0['substitution-key']['substitution-key']Passed
substitution-key regression 1['substitution-key']['substitution-key']Passed
universe-key regression 0['universe-key']['universe-key']Passed
universe-key regression 1['universe-key']['universe-key']Passed
edge-kind-key regression 0['edge-kind-key']['edge-kind-key']Passed
edge-kind-key regression 1['edge-kind-key']['edge-kind-key']Passed
layout-key regression 0['layout-key']['layout-key']Passed
layout-key regression 1['layout-key']['layout-key']Passed
negative-fact-invalidation regression 0['negative-fact-invalidation']['negative-fact-invalidation']Passed
negative-fact-invalidation regression 1['negative-fact-invalidation']['negative-fact-invalidation']Passed
provisional-result regression 0['provisional-result']['provisional-result']Passed
provisional-result regression 1['provisional-result']['provisional-result']Passed
diagnostic-span-rebind regression 0['diagnostic-span-rebind']['diagnostic-span-rebind']Passed
diagnostic-span-rebind regression 1['diagnostic-span-rebind']['diagnostic-span-rebind']Passed

SHA-256 / 1f1da2f0017130e4f2c3dfbb39e6eacd30d5524b424e8c784395a51672d0e7ad

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 21 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.

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Verification & scope

The explicitly stated toy language is the complete scope; this is not a production compiler or a claim about Rust semantics. 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 2026-09-29T14:44:10.729342+00:00.

Case digest / 7caef8b7b57da65708bd22941b334290b21fe017628990960b48be4ad423b476