datasource-autoconnect.test.ts federated-query case fails locally on clean main — engine.find returns 8 duplicated rows for 2 seeded (CI green, so likely environment-sensitive) #4102

Hit while running the @objectstack/runtime suite for unrelated work. Filing rather than chasing it, since it is not mine and not obviously broken for everyone.

Symptom

packages/runtime/src/datasource-autoconnect.test.ts → ADR-0062 declared-datasource auto-connect › makes the federated object queryable through the engine with zero app code:

AssertionError: expected [ 'first', 'first', 'first', …(5) ] to deeply equal [ 'first', 'second' ]

The test seeds exactly two rows into the live external driver and reads them back through the engine:

await driver.bulkCreate('ext_note', [{ id: 'n1', title: 'first' }, { id: 'n2', title: 'second' }]);
const rows = await engine.find('ext_note');
expect(rows.map((r) => r.title).sort()).toEqual(['first', 'second']);

engine.find returns eight rows, and the sorted head is all 'first' — so the federated read is multiplying rows rather than returning the two that were written.

Reproduction / scoping

• Clean main at 7ac1995, fresh full pnpm build, node v22.22.2.
• Fails both in the full package suite (1 failed | 913 passed) and when the file is run alone (1 failed | 9 passed), so it is not cross-file order pollution.
• Reproduces with unrelated local edits stashed, so it is not caused by them.

Important caveat

CI's Test Core job was green on #4084 against this same base, so this does not reproduce everywhere — it is likely sensitive to something environmental (driver/adapter build, platform, or a timing assumption in the federated read path) rather than plainly broken on main. Worth someone confirming whether the runtime suite's datasource-autoconnect case is actually in CI's scope, because if it is and it passes there, the row multiplication is real but conditional — and a conditional duplicate-rows bug in the federated read path is worth more than a flaky-test label.

I have not investigated the cause.