clay-borg/tools/__pycache__/cb-cost.cpython-312.pyc
tegwick 1c3019c7e8 CB-WP-0006 T02: instrument AM-2; report AM-3 blocked, with the argument
Both rows were unmutatable for the same stated reason. They resolved
differently, and the difference is the point.

AM-2 is instrumented and enforced — tools/size-metrics.py, in `make all`:

  AM-2: 27.2 LOC/rule  [ok  target <= 40]  (1.47x headroom)
        1,575 impl lines / 58 rules

Tests are excluded because AM-2 asks what a rule costs, not how much it is
exercised; lib.rs is ~18% test code and including it would have flattered
the number. This matters because AM-2 is AM-1's anti-gaming pair: 100%
rule coverage means nothing if the rules are trivially small, and AM-1 has
been reported met since CB-WP-0001 with its pair uninstrumented.

Verified red by a property mutation — ~800 lines of filler injected into
the impl, pushing the ratio past 40 — not a threshold tweak. The expect
string is the precise failure signature "FAIL target <= 40"; my first
attempt used "AM-2", which also matches passing output and would have
made the FA guard vacuous.

AM-3 is BLOCKED, not uninstrumented, and that is a finding rather than a
deferral. It measures LOC to express the CB-RES-0001 synthetic game on our
kernel, against a boardgame.io baseline of ~36 LOC for a declarative 3p
commit/reveal game object. That artifact has never been built: games/
contains only ground, and benches/synthetic.rs drives GROUND rather than
defining a synthetic game. Measuring GROUND's 1,575 impl lines against a
36-line synthetic game object would compare two different games and call
the difference a D1 result.

So the tool ships the measurement — a marker-delimited region, self-tested
— and reports the row blocked, naming the missing artifact. A number would
have been worse than a blank. It stays unmutatable and still counts
against M-D1-MUT per ADR-0005 §1: a row that cannot fail asserts nothing,
however good the reason.

M-D1-MUT: 5 -> 6 of 14.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-31 18:38:15 +02:00

36 KiB