Defects we have reproduced in the UCP reference stack

expected each pinned constraint rejects its negative payload

observed the older named probe, conformance/selfcheck/sdk_constraints_probe.py, does NOT run against 0.5.0: it imports ucp_sdk.models.schemas.shopping.types.context, which moved to common.types.context when ucp#741 moved the shared types out of shopping. The gate above is what measures this every run; the 2026-10-09 nightly read pydantic-tag 0.5.0 agree 13, acknowledged drops 7, NEW 0, stale 0, expired 0. All four upstream fixes merged 2026-09-01 and 09-04 but the 0.5.0 tag was cut 2026-08-27, before them, so the tag still drops. See known_sdk_drops.json

expected generated declarations carry the extends/maxProperties members

observed 0.5.1 lacks them; main has them

expected ZodRecord (object keyed by capability name)

observed ZodArray at 0.5.1 (re-run 2026-10-11 against the published package: capabilities typeName ZodArray; spec_generated.js:1560 reads `capabilities: z.array(CapabilityDiscoverySchema)`)

expected a validation verdict

observed exit 134 with a stack overflow abort in the main thread, on both the installed 1.4.1 and the vendored pinned build, re-run 2026-10-11 with the recipe recorded in ucp-schema#45. An earlier re-read of this row probed payment_split_payments.json --def dev.ucp.shopping.checkout, which is not the crash pattern and exits 1 with a clean validation error, and wrongly recorded the row as not reproducing

expected all tests OK

observed all tests OK at the current pin cdb291c4 (279 passed, 12 subtests, no 500s and no checkout_service reference); the former path rest/python is not a uv project root and never was; only rest/python/server carries a pyproject, at both the old and the new pin

expected server listens

observed re-run 2026-10-11 at pin cdb291c4: npm run build exits 0 and emits dist/src/index.js but no dist/index.js, so npm start throws; node dist/src/index.js fails ERR_MODULE_NOT_FOUND on dist/src/api/checkout. 39 extensionless relative imports across 13 emitted files (was 37)

expected a 2026-08-25 default or matrix

observed "2026-04-08" only

expected tag v2026-04-08 == the locked commit (a25a4a24 since 2026-09-11)

observed sources-age: OK — all 4 pinned spec tag(s) still carry their locked identity (tag object + dereferenced commit); before the re-pin: TAG MOVED v2026-04-08 -> a25a4a24 (acknowledged)

expected one unambiguous comparison rule

observed the former command named a --only flag that golden_check_08_25.py does not define, so it selected nothing and ran the whole module. The real implementation is conformance/ci/seq_invariants.py I10 replay_reserialized, whose mode comes from conformance/ci/replay_mode.json. Latest measurement: 2776 I10 hits over 27818 requests and 4751 sequences, counted as PENDING D3-23 because golden-0825 still hashes the parsed body (checkout_service.py _compute_hash, sort_keys) while the spec matches raw body bytes

expected UCP error envelope 404

observed 404 with the UCP envelope as of 2026-10-11: {"ucp":{"version":"2026-08-25","status":"error"},"messages":[{"type":"error","code":"not_found","content":"Not Found","severity":"unrecoverable"}]}. It answered FastAPI {"detail":"Not Found"} before C3 (D3-04)