fix(desktop): take desktop tests off the master push lane

[gantoine]

Problem

• A desktop pull request or merge queue batch waits up to 76 minutes for a macOS test that runs in 6 minutes. Run 34207978083 queued 76 minutes, ran 5.9, and passed.
• depot-macos-26 is a fixed pool shared across Depot customers, with no autoscaling, because Apple requires a 24-hour minimum lease. We can change how often we join that queue, not our position in it.
• The waits are not self-inflicted. For 71 of those 76 minutes, no PostHog macOS job was running at all. The most PostHog macOS jobs seen running at once, over three weeks, is two.
• Master pushes make most of the requests. Every products/desktop/** push asks for two macOS runners: the integration test and the macOS cache warmer.

Jobs on depot-macos-26 over 24 hours, from the GitHub jobs API:

Lane	Jobs	Run minutes	Queued minutes
master push, desktop-test integration test	24	135	337
master push, desktop-warm-caches	23	87	287
pull request	8	63	0
release tag	4	45	0
merge queue batch	3	20	1
master push, desktop-update-e2e	1	9	0

• fix(desktop): skip the macOS integration test on merge queue batches #96546 cut the merge queue batch lane, which is 3 of those 63 jobs. It also removed the one run that tests the tree that lands.

Changes

• desktop-test.yml stops running on master pushes. A daily 05:03 UTC cron carries master coverage instead. Nothing dispatches on a desktop push, so the Linux jobs stop repeating the batch as well.
• The merge queue batch tests macOS again. This reverts fix(desktop): skip the macOS integration test on merge queue batches #96546, so the batch keeps covering the merged tree.
• desktop-warm-caches now fires only when products/desktop/pnpm-lock.yaml changes. Every cache key in that workflow hashes that one file, and its install steps already no-op when all three caches hit, so the other runs took a macOS runner to learn they had nothing to do.

Across the last 7 days the master lane drops from 100 macOS jobs, from 50 pushes, to 23: 7 scheduled plus 16 lockfile changes.

The diff removes more lines than it adds. Skipping the workflow beats guarding the macOS job by event, which would leave the run dispatching and the Linux jobs repeating work the batch already did.

Note

The e2e job needs integration-test, so the live-model gateway suite follows this schedule on master. It still runs on every pull request and every batch. Its pnpm cache save keys off github.ref, which a cron run still satisfies.

Before:

flowchart LR
    A["desktop PR"] --> M1["macOS integration test"]
    B["merge queue batch"] --> S1["skipped by #96546"]
    C["master push"] --> M2["macOS integration test"]
    C --> M3["macOS cache warmer"]
    classDef phBlue fill:#1d4aff,stroke:#1d4aff,color:#fff;
    classDef phRed fill:#f54e00,stroke:#f54e00,color:#fff;
    classDef phGray fill:#e5e7eb,stroke:#c7ccd1,color:#000;
    class M1 phBlue;
    class M2,M3 phRed;
    class S1 phGray;

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After:

flowchart LR
    A["desktop PR"] --> M1["macOS integration test"]
    B["merge queue batch"] --> M2["macOS integration test"]
    C["master push"] --> S1["no run"]
    D["daily 05:03 UTC"] --> M3["macOS integration test"]
    E["pnpm-lock.yaml push"] --> M4["macOS cache warmer"]
    classDef phBlue fill:#1d4aff,stroke:#1d4aff,color:#fff;
    classDef phYellow fill:#f9bd2b,stroke:#f9bd2b,color:#000;
    classDef phGray fill:#e5e7eb,stroke:#c7ccd1,color:#000;
    class M1,M2 phBlue;
    class M3,M4 phYellow;
    class S1 phGray;

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How did you test this code?

• No tests were added. The change is a trigger and a job condition, and this repo has no harness that evaluates a GitHub Actions if: expression.
• actionlint, bin/hogli lint:workflows and bin/hogli ci:preflight all pass on this branch.
• The queue and run times come from the jobs API over recent runs of desktop-test.yml, desktop-ci.yml, desktop-warm-caches.yml, desktop-update-e2e.yml and desktop-release.yml. Push frequency comes from git log over origin/master.
• The workflow was read for anything else the push lane carried. Only the e2e job's pnpm cache save is ref-scoped, and a cron run keeps github.ref at refs/heads/master.
• Not verified: that the cron fires, and that a desktop master push now dispatches nothing. Both need a run on this trigger, which exists only once this lands.
• No manual testing. A workflow trigger cannot be exercised locally.

Automatic notifications

• Publish to changelog?

Docs update

None. The change affects CI scheduling only.

🤖 Agent context

Autonomy: Human-driven (agent-assisted)

Raised from a Slack thread about slow desktop tests. The thread's working diagnosis was contention on the macOS pool, so the first fix cut merge queue demand (#96546). The job timings then showed the long waits happen while PostHog's own macOS jobs sit idle, which moved the target from the batch lane to the master-push lane, and made reverting #96546 part of the fix rather than a reversal of it.

Skills invoked: /authoring-ci-workflows and /writing-pr-descriptions.

Two rounds of review from the driver shaped the result. The first draft guarded the macOS job with github.event_name != 'push' and kept the trigger, which still dispatched a run per desktop push; skipping the workflow replaced it. The cron started at six-hourly, until measured push frequency made that a 44% cut.

On cadence: the hourly master lane in /authoring-ci-workflows is the documented pattern for this substitution, and hourly cannot work here, because 24 runs a day is what this PR removes. Daily master crons are already common in this repo, including for suites: ci-hobby.yml at 06:00, ci-e2e-playwright-audit.yml at 07:00, ci-storybook-update-test-timing.yml at 04:00, and desktop-update-e2e.yml, which runs a depot-macos-26 job daily at 07:00. ci-geoip-canary.yml runs six-hourly. So the cadence is in-house, but this is the first daily lane that replaces a suite's master-push coverage.

desktop-test.yml is in neither GATING_WORKFLOWS nor SCHEDULED_GATING_WORKFLOWS in ci-alerts-devex.yml, so no desktop lane pages today. Registering the new cron there is a follow-up: the alerter's scheduled thresholds assume an hourly cadence, and a daily lane needs its own arms.

No duplicate: #95852 and #94509 are open drafts on the same pool. Both cut the time a job spends on a macOS runner; neither cuts how many runners the repo asks for.

The diff carries no customer data or other non-public material.

[trunk-io]

😎 Merged successfully - details.

[github-actions]

🤖 CI report

⚠️ Trunk lane — backend Python lane

This PR is assigned to the backend Python lane. It runs backend Python tests and may merge in parallel with PRs in other lanes.

[Copilot]

🟡 Changes recommended

The new scheduled lane’s intent is partially undermined by missing DevEx alerter registration (and there’s also a cron/comment mismatch that should be corrected).

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Pull request overview

Adjusts Desktop CI workflow triggers to reduce contention on the fixed depot-macos-26 runner pool by eliminating macOS runner usage on master pushes, while preserving macOS coverage via the merge queue lane and a scheduled post-merge run.

Changes:

• Limit desktop-warm-caches to run only when products/desktop/pnpm-lock.yaml (or the workflow) changes.
• Add a daily scheduled run for desktop-test and isolate its concurrency group from push runs.
• Skip the macOS integration-test job on master push events (so macOS coverage comes from PRs/merge queue + schedule instead).

File summaries

File	Description
.github/workflows/desktop-warm-caches.yml	Narrows push trigger paths so cache warming only consumes macOS capacity when the lockfile (cache key input) changes.
.github/workflows/desktop-test.yml	Adds a scheduled post-merge lane and updates concurrency; prevents macOS integration tests from running on master pushes.

Review details

• Files reviewed: 2/2 changed files
• Comments generated: 2
• Review effort level: Lite

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[greptile-apps]

Prompt To Fix All With AI

### Issue 1
.github/workflows/desktop-test.yml:30
**Concurrency key can collide**

The literal `scheduled` key can match a pull request whose branch is also named `scheduled`. Because pull request runs cancel in-progress jobs in the same group, that branch could cancel the daily macOS run and remove the post-merge coverage this change relies on. Use a namespaced key that cannot overlap with a branch name.

```suggestion
    group: desktop-test-${{ github.event_name == 'schedule' && 'event-scheduled' || github.head_ref || github.ref }}
```

---

For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.

_{Reviews (1): Last reviewed commit: da6b745 | Re-trigger Greptile}

[deployment-status-posthog]

Deploy status

Environment	Status	Deployed At	Workflow
dev	✅ Deployed	2026-09-08 18:22 UTC	Run
prod-us	✅ Deployed	2026-09-08 18:39 UTC	Run
prod-eu	✅ Deployed	2026-09-08 18:41 UTC	Run