synthetic-unsupported-version._expectations.md (SYNTHETIC)

All samples in this directory are synthetic, rather than extracted native sessions. The historical unsupported-version directory name is retained from V17 rejection tests. From V30, OMP unknown versions attempt latest_fallback; this document and assertions describe that newer behavior.

Scenario and expectations (V30: unregistered or absent version attempts the latest parser)

Older OMP disk formats are unverified, without established incompatibility. Pi v1/v2, by contrast, were proven incompatible by fixed source and remain rejected. For OMP, both unregistered numeric versions and absent version use LatestFallback with session_v3. V30 scanning determines structural incompatibility: records read, zero events and structural diagnostics retain previous results.

...d020.jsonl, three lines: session version=4 (only 3 locally verified). detect returns Supported{format=omp-session-jsonl, format_version=Some(“4”), basis=latest_fallback}.
...d021.jsonl, three lines: session has no version; legacy-shaped entry id=syn-l1 differs from d020’s syn-m1. V17 used syn-m1 in both because no events were imported; compatibility fallback would create a false same-key/different-content conflict, so these now have distinct IDs. detect returns Supported{format_version=None, basis=latest_fallback}.
Both scan successfully: file status=“complete”, one event each with 100/10/0/0/110. Detail includes latest_fallback: version compatibility unverified (found: 4|missing). Two usage_events have parse_basis=latest_fallback, schema_version=“4” and “unknown”. Both source_files have status=“active_compat” and format_status basis=latest_fallback, compat=unverified, found_version=“4” and null. Two latest_fallback diagnostics, one per file.
Summary (2026-01-05 UTC): call_count=2, input_total=200 (derived input+cacheRead+cacheWrite, 100 each), output=20, total_tokens=220.
Repeat scanning adds nothing after the cursor is consumed: added=0.