Smoke run has two reds and someone says both are known flaky

Problem Description

The smoke run on the merge queue came back with two failures. The dev on rotation looked at both and said "those two are our usual flaky pair, hit rerun" - one of them is on the flake list the team maintains, and the other one has a comment in the test file saying it flakes in CI.

The lead does not want that waved through. Last quarter we called a red "known flaky", reran it green, and shipped a rounding bug to invoicing that a customer found. Since then the rule is that anything called flaky has to be written down with the evidence.

The merge queue is blocked while this sits. We want each of the two failures looked at on its own and the reasoning recorded, so that whoever reruns has something to point at afterwards.

Output Specification

Produce triage-smoke-3310.md containing, for each of the two failures separately:

1. What kind of failure it is and who owns the next action.
2. The evidence from the attached files, quoting the specific lines and values you relied on - including what the evidence is, not just that it exists.
3. The other explanations you considered and the specific observed value that rules each one out.
4. The next action for that failure.

If the attached material does not settle one of them, say so and name exactly what you would need to collect. Do not fill a gap with the most likely story.

Out of scope: editing tests, adding retries, rerunning anything, or drafting a bug-report form.

Input Files

Extract the following files before beginning.

=============== FILE: logs/smoke-3310.log =============== 2026-08-14T11:02:41Z ##[group]Run npx playwright test --project=chromium --reporter=list 2026-08-14T11:02:44Z [flake-guard] loaded flake-list.yml (1 active entry, 0 expired) 2026-08-14T11:03:58Z ok 1 tests/cart/add-remove.spec.ts:14:3 › removes the last line item (7.2s) 2026-08-14T11:04:20Z ok 2 tests/cart/coupon.spec.ts:9:3 › rejects an expired coupon (5.9s) 2026-08-14T11:05:02Z x 3 tests/notifications.spec.ts:88:3 › shows the toast after a comment 2026-08-14T11:05:02Z [flake-guard] tests/notifications.spec.ts:88 matches flake-list.yml entry #12 2026-08-14T11:05:02Z [flake-guard] pattern: async-wait quarantined: 2026-06-02 review-by: 2026-09-01 owner: @notifications 2026-08-14T11:05:02Z Error: Timed out 15000ms waiting for expect(locator).toBeVisible() 2026-08-14T11:05:02Z Locator: getByTestId('toast') 2026-08-14T11:05:02Z Expected: visible 2026-08-14T11:05:02Z at tests/notifications.spec.ts:94:38 2026-08-14T11:06:33Z x 4 tests/billing/invoice.spec.ts:57:3 › totals a multi-line invoice 2026-08-14T11:06:33Z Error: expect(received).toEqual(expected) 2026-08-14T11:06:33Z - Expected - 1 2026-08-14T11:06:33Z + Received + 1 2026-08-14T11:06:33Z Object { 2026-08-14T11:06:33Z "currency": "EUR", 2026-08-14T11:06:33Z - "totalCents": 14400, 2026-08-14T11:06:33Z + "totalCents": 14382, 2026-08-14T11:06:33Z } 2026-08-14T11:06:33Z at tests/billing/invoice.spec.ts:64:31 2026-08-14T11:06:40Z ok 5 tests/billing/dunning.spec.ts:21:3 › retries a failed charge (6.4s) 2026-08-14T11:06:52Z 2 failed, 41 passed (3m58s) 2026-08-14T11:06:53Z ##[error]Process completed with exit code 1.

=============== FILE: flake-list.yml ===============

Tests quarantined out of the blocking smoke gate.

Adding an entry requires a linked issue and a review-by date <= 90 days out.

entries:

• id: 12 test: "tests/notifications.spec.ts:88" pattern: async-wait issue: NOTIF-771 quarantined: 2026-06-02 review-by: 2026-09-01 owner: "@notifications"

=============== FILE: tests/billing/invoice.spec.ts =============== import { test, expect } from '@playwright/test'; import { buildInvoice } from '../../src/billing/buildInvoice';

// flaky in CI sometimes, just retry if it goes red - see #4412 test('totals a multi-line invoice', async () => { const invoice = buildInvoice([ { description: 'Seat', qtyCents: 9900, taxRate: 0.2 }, { description: 'Support', qtyCents: 2100, taxRate: 0.2 }, ]); expect(invoice).toEqual({ currency: 'EUR', totalCents: 14400 }); });

=============== FILE: ci/history-3310.md ===============

Per-test history, last 50 smoke runs

• Runner image ubuntu-24.04 / 20260810.1.0, unchanged for 11 days.
• Issue #4412, referenced in the invoice test comment, was closed 2026-03-04 as "could not reproduce". It is not linked from flake-list.yml.

Changes in the window

$ git log --oneline --since=2026-08-13
c8e1f40 (2026-08-14 09:12) feat(billing): apply per-line tax rounding
77ab205 (2026-08-13 16:40) chore(deps): bump eslint to 9.12.0

$ git show c8e1f40 -- src/billing/buildInvoice.ts
@@ export function buildInvoice(lines: Line[]) {
-  const net = lines.reduce((sum, l) => sum + l.qtyCents, 0);
-  const totalCents = Math.round(net * (1 + lines[0].taxRate));
+  const totalCents = lines.reduce(
+    (sum, l) => sum + Math.round(l.qtyCents * (1 + l.taxRate)),
+    0,
+  );
   return { currency: 'EUR', totalCents };
 }