Twelve injection pairs, both sides, K=5, temperature 0, thinking disabled,
recording every tool call. $0.23.
The statistic I designed for could not be computed: across 120 runs there was
not one repeated trajectory -- 4.67 and 4.92 distinct trajectories per side
out of 5, and 78 distinct tool-name sequences ignoring arguments entirely.
The detector is not sampling one measurement five times; it is running five
different investigations and voting on the results.
As a gradient the relationship is monotone: runs whose trajectories were
similar (>=0.75 Jaccard) disagreed 0% of the time, mid-similarity 4.2%,
low-similarity 30.9%.
Three more facts. The search is grep: 555 grep_repo calls against 181
read_file, 71 entry_points, 43 find_refs, 13 read_definition -- the model is
guessing patterns to locate sinks the CST and the entry-point mapper already
know. All the instability is on the vulnerable side; every pair produced
exactly one finding set on the fixed side, so the noise is in detection and
none of it in false positives. And findings converge much more than
trajectories do: 78 trajectories, one to three finding sets per pair.
The floor is therefore not measuring uncertainty about a question. It is
measuring how often an unconstrained search happens to reach the sink.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG
The three gate outputs are captured at 71efc9c -- the commit before the
first line of this feature -- and a test reproduces them byte for byte in
both matrices. Byte-identity was something a reviewer checked by hand
against a worktree; it is now mechanical and runs in CI.
Six absences are each exercised once with the reason they record: HarnessX,
the chat endpoint (the run still writes its artifact), the family
configurations, the network for pointer pairs, the semantic extra (named,
not guessed), and the sandbox -- so a claim nothing could run is not
confused with a claim that failed.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG
The five byte-identical vibe-py twins now say so in the catalog instead of
only hashing to it, and a declared limit that names one of the unscorable
vocabulary's own reasons keeps that spelling, so `identical_twin` stays one
fact. Leave-one-out over vibe-py consequently runs on 30 rows, not 35.
The difficulty check measures three axes the corpus varies on: binding hops
from the identity source to the constrained use, registration distance, and
guard distance. Measured first, and it failed: the shared obligations
fixture reached (1, 0, 2) where the vibe-py absence rows reach (5, 2, 2).
Every fixture handler carried its own route decorator, so nothing in the
suite exercised a handler registered from another document and no binding
chain was longer than one hop -- the checker was passing on a simpler world
than the one it meets. `from_spec` closes that with the connexion shape
those rows really have. The verdict is committed beside the numbers.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG
Eight of the ten vendored access-control rows had no named handler at all,
so every one of them would have scored `missing_context` forever rather
than as a detector miss. After the re-harvest nine are named and the tenth
states its reason.
The handler-context mode now carries the class its framework registers,
multi-line decorators, and commented-out guards -- `#@token_required`
above a ThreatByte handler is the entire bug. Where the registration lives
in another document (connexion's `operationId`, an express router), a
recipe names `context = [...]`, the harvester writes that stanza per side,
and the pair materializes both files at their repository-relative paths so
the entry-point mapper sees the layout the project has. `harvest_recipe`
fetches every blob before the first write and the driver takes `--report`,
so a failed fetch leaves a reviewed excerpt exactly as it was.
Two defects the re-harvest exposed: `.mjs` was not a known suffix, so the
one pair vendored as an ES module had no file target at all; and
`_python_route_access` matched auth words inside decorator prose, reading
`@ns.doc(description='... without proper authorization checks')` as a
guard. Recorded in the hygiene artifact: nine of the ten duplicate groups
sit on both sides of the split, which the repository-level split cannot
see.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG
Task 3.1. A teacher is a vendored pair, at a review tier a maintainer stands
behind, on the train split, and scorable. Every learning path now asks the same
module that one question, so the split cannot be enforced in one place and
forgotten in another. A refusal is data rather than an exception: the path
records which holdout pairs a candidate touched and moves on, so a leak is
visible in the run instead of silently accepted.
The exporter refuses to seed from a holdout pair, leave-one-out teaches from the
train split while still scoring every pair, and the mechanism lever refuses a
candidate a holdout pair taught, because such a shape can only recover the pair
that produced it.
Measured and committed: on the vibe-py holdout the lever's own number falls from
seven detected and a Youden of +0.059 to five detected and -0.059 once holdout
pairs stop teaching, and the candidate set shrinks from ten shapes to six. That
gap is the inflation this rule removes.
Two existing tests encoded the leak and now encode the truth. The documented
export-to-improve flow had a single holdout pair teaching itself, and now needs
a train pair to teach and a holdout pair to recover. The obligation export
claimed the corpus seeds at least one obligation shape, which was true only
because holdout pairs were teaching: every vibe-py absence pair that yields an
obligation lesson sits on the holdout side, so the honest number today is zero.
The derivation stays covered by fixtures; the corpus gap belongs to the absence
re-harvest and to a maintainer pass over the splits.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG
Task 1.3. An expected row may carry a family label, stored opaquely because the
classifier owns the taxonomy and the corpus module never imports the learning
package. Every pair carries a computed reason when it cannot be scored: a
declared known limit wins, otherwise identical twin when the two excerpts are
the same code once the provenance header is stripped. No row is ever dropped.
Two corpus defects the new accounting surfaces, committed as an artifact beside
the numbers they cap. Nineteen repositories sit on both sides of the split, so a
learning path could be taught by one file of a repository and evaluated on
another. Ten groups of pairs share a vulnerable excerpt byte for byte, mostly
the same fix harvested twice at different granularity.
The split helper keeps every declared split, lets rows that named none inherit
their repository's side, and otherwise assigns a whole repository at once,
oldest first, so nothing straddles by our doing. Pair signals can now be
restricted to one split, which is what lets a learning path teach from train
rows only.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG
Measured 2026-09-06 on the vibe-py holdout: the existing tool hunter, with no
learning, scores 12/14 pair-correct (Youden +0.857, no leaks) once detection
and silence are keyed on the labeled class and function and the byte-identical
twins are excluded; the overlay scores 5/14 on the same rows. The published
hunter number (0/17, Youden -0.588) was a scoring artifact: the scorer wanted
the literal CWE id in the finding text and the prompt never asked for it.
The brief proposes an auto-classifier as the routing key, one evolved hunter
configuration per class, a class-aware scorer with unscorable denominators,
the split enforced by construction, and the HarnessX evolve loop with per-class
attribution as the round primitive. Raw measurements are committed under
reports/measurements.
Co-Authored-By: Claude Fable 5.1 <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG
