manual_slop/docs/reports/campaign_measurements_20260624.md

Campaign Measurements: metadata_ssdl_defusing_20260624

Tracking effective codepath counts at each child of the campaign.

Baseline

Source: docs/reports/code_path_audit/2026-06-22/AUDIT_REPORT.md Finding 1.

Metric	Value
Effective codepaths (Metadata)	4.01e22
Nil-check functions (per SSDL rollup)	74
Nil-check functions (per spec text "the 6")	6 (stale count from executive summary)

Note: The "6 nil-check functions" count in the executive summary is a static text string in src/code_path_audit_gen.py, not a runtime measurement. The actual SSDL detection finds 74 functions across the codebase, of which 1 is in src/aggregate.py and 27 are in src/ai_client.py.

Child 1: metadata_nil_sentinel_20260624

Metric	Value
Effective codepaths (post-child-1)	4.014e22
Drop vs baseline	-0.1% (slight increase; within rounding error)
Budget gate (10% drop)	FAIL
NIL_METADATA defined	YES (src/aggregate.py:50)
Functions migrated	1 (_build_files_section_from_items in src/aggregate.py)
Behavioral tests	5/5 PASS

Budget Gate Finding

The 10% drop threshold is mathematically near-impossible to achieve with this measurement for two reasons:

1. Exponential dominance: the effective-codepath sum is dominated by 2^N where N is the largest branch count. Removing 1 branch from a function with N=10 branches drops that function from 2^10=1024 to 2^9=512 — a 50% reduction for that function, but the total sum changes by less than 1 part in 4e22.

2. SSDL detection is textual: detect_nil_check_pattern returns True for any function that has is None / == None / != None patterns, regardless of whether the variable is Metadata-typed. Most of the 74 detected functions have nil-checks on _gemini_client, _anthropic_client, path, adapter, etc. — not on Metadata values. The sentinel migration pattern (X = X or NIL_METADATA) only applies cleanly when X is Metadata-typed.

Interpretation

The campaign's value is in the structural improvement, not the final heuristic number. The campaign spec itself acknowledges this risk: "R4: The cumulative drop is less than expected... If the techniques ship, the campaign succeeds regardless of the final heuristic number."

Child 1's contribution:

• NIL_METADATA primitive is now defined and reusable (it serves as the fallback path for Child 2's generational-handle generation-mismatch case).
• 1 demonstration function (_build_files_section_from_items) shows the pattern works end-to-end.
• 5 behavioral tests document the contract.

Children 2 and 3 can build on the primitive. The 10% threshold is unlikely to be met by any single child; the cumulative campaign effect is what matters.