fix(ci): stop each HTTP end-to-end app fully and start the next from an empty dev cache by waleedlatif1 · Pull Request #8686 · simstudioai/sim

waleedlatif1 · 2026-10-06T18:15:18Z

Summary

The "End-to-end over real HTTP" job's stop-after step (test-workflow-stop-after-e2e.ts) was flaky. This was test infrastructure, not a product bug: no failed run ever reached the executor.

Root cause. All the apps in the job share apps/sim/.next. The stop-after app restored the Turbopack dev cache (.next/dev) that the job's previous app, the SCIM/version-compare one, left behind. That cache was built with different NEXT_PUBLIC_* values by a server that next dev SIGKILLs 100ms after SIGTERM (NEXT_EXIT_TIMEOUT_MS defaults to 100). The step also started while the previous app could still be writing that directory: kill plus wait on next dev returns before its server process tree is gone. An earlier revision of this PR hit that directly. Its rm -rf .next/dev failed with Directory not empty 1s after the previous step ended.

I classified every failed run of this step across 175 CI runs from Oct 1 to Oct 6. 12 were this flake, and all 12 came from the restored cache:

Symptom	Runs	What the server log shows
`Local workflow app exited during startup`	6	Turbopack panic `inner_of_upper_lost_follower ... aggregation_update.rs`
`The socket connection was closed unexpectedly`	4	the same panic while compiling `/api/v2/workflows/[workflowId]/execute`
`The operation timed out.` after 5 min	2	`○ Compiling /api/v2/workflows/[workflowId]/execute ...` that never finishes, with JS heap flat

The other 2 failed runs had real branch errors. In the timed-out runs the cleanup check found no open execution log, so the first request never reached the handler. That rules out a stop-after run that never terminates. Healthy runs of this step took 35–99s (p50 47s).

Changes

CI (test-build.yml), for all three app steps:
- Each app starts in its own session (setsid).
- The new .github/scripts/stop-session.sh sends SIGTERM to the whole session and returns only once none of it is left running. It escalates to SIGKILL after 10s and fails the step if anything survives that. It logs any process that outlived next dev.
- Each app then starts from an empty dev cache (rm -rf .next/dev).
- A failing step prints the server log tail, not only on a startup failure.
Stop-after suite:
- A named first check compiles the execute route with a refused request under its own 300s budget.
- Every later request and CLI run is bounded at 60s.
- A timed-out or dropped request names the route and the elapsed time. It lands in the report with status: null, so a status is recorded only for a fully read response.
- A CLI timeout is reported as a timeout, and an unexpected CLI failure reports its stderr.
Desktop inbox suite (feat(desktop): bind turns to a desktop and enforce its deadlines from the row #8650): a cold cache exposed that its 10s "all four calls" deadline also covered next dev compiling the claim, lease and complete routes. One CI attempt failed that way. A new check now compiles those three routes with refused bodies before the timed checks.

Evidence

Local: a CI-faithful harness on the Mac (5 iterations) and a targeted SIGTERM-then-restore loop (5 cycles) both passed. The panic didn't reproduce on darwin-arm64.
Linux EC2 (8 cores via taskset), unchanged code: 8 of 8 iterations passed. On a quiet box the flake doesn't reproduce, and no process outlived next dev there.
Linux EC2, this PR: 8 of 8 two-step iterations and 6 of 6 three-step iterations passed. A cold cache moves the stop-after step from ~58s to ~105s.
CI reruns of the http-e2e job on this PR: see the comment thread.
Gate (EC2): lint, typecheck, audits, migrations, docs, blocks and test all pass. In test, 3 unrelated files failed under load and passed when rerun alone.

waleedlatif1 · 2026-10-06T18:15:23Z

@greptile

waleedlatif1 · 2026-10-06T18:15:24Z

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vercel · 2026-10-06T18:15:25Z

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Project	Deployment	Actions	Updated
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cubic-dev-ai · 2026-10-06T18:15:31Z

@cubic-dev-ai review this PR

@waleedlatif1 I have started the AI code review. It will take a few minutes to complete.

cubic-dev-ai

No issues found across 2 files

Confidence score: 5/5

Automated review surfaced no issues in the provided summaries.
No files require special attention.

_{Turn on auto-fix | Re-trigger cubic}

greptile-apps · 2026-10-06T18:20:00Z

Confidence Score: 5/5

[High risk] Changes CI process for end-to-end test isolation and timing.

The PR appears safe to merge; no outstanding findings or new actionable defects remain.

Summary

The PR gives each HTTP end-to-end app a separate process session, waits for cleanup before the next app starts, and clears the shared Turbopack dev cache. It also adds route warm-up checks and improves stop-after suite timeouts and diagnostics.

Diagram

%%{init: {'theme': 'neutral'}}%%
flowchart LR
  A[Clear .next/dev] --> B[Start next dev in its own session]
  B --> C[Run HTTP end-to-end checks]
  C --> D[Stop and wait for the session]
  D --> E[Start the next app]

_{Reviews (3) · Last reviewed commit: "fix(e2e): compile the desktop executor r..."}

waleedlatif1 · 2026-10-06T18:26:37Z

@greptile

waleedlatif1 · 2026-10-06T18:26:38Z

@cubic-dev-ai review this PR

cubic-dev-ai · 2026-10-06T18:26:42Z

@cubic-dev-ai review this PR

@waleedlatif1 I have started the AI code review. It will take a few minutes to complete.

cubic-dev-ai

No issues found across 2 files

Confidence score: 5/5

Automated review surfaced no issues in the provided summaries.
No files require special attention.

_{Turn on auto-fix | Re-trigger cubic}

…ache The stop-after suite failed 12 of 175 CI runs (Oct 1-6), always in its own `next dev` app, which restored the Turbopack dev cache (.next/dev) the SCIM/version-compare app left in the same job. That app ran with other NEXT_PUBLIC_* values, and `next dev` SIGKILLs its server 100ms after SIGTERM. Restoring the cache: - panicked Turbopack at startup (inner_of_upper_lost_follower), 6 runs; - panicked mid-compile of the execute route ("socket connection was closed unexpectedly"), 4 runs; - wedged that compile until the 300s request timeout ("The operation timed out."), 2 runs. No run reached the executor: the cleanup check found no open execution log. - Each app step removes .next/dev before starting, so no app restores another app's cache. - A failing step prints the server log tail, not only a startup failure. - The suite compiles the execute route with a refused request under its own 300s budget and named check; every later request and CLI run is bounded at 60s. A timed-out or dropped request names the route and elapsed time, lands in the report with a null status, and a CLI timeout is reported as one.

…e too

… the next one starts

…calls

waleedlatif1 · 2026-10-06T21:02:40Z

@greptile

waleedlatif1 · 2026-10-06T21:02:41Z

@cubic-dev-ai review this PR

cubic-dev-ai · 2026-10-06T21:02:47Z

@cubic-dev-ai review this PR

@waleedlatif1 I have started the AI code review. It will take a few minutes to complete.

cubic-dev-ai

No issues found across 4 files

Confidence score: 5/5

Automated review surfaced no issues in the provided summaries.
No files require special attention.

_{Turn on auto-fix | Re-trigger cubic}

waleedlatif1 · 2026-10-06T22:01:57Z

CI evidence for head bd1e89d: I reran the "End-to-end over real HTTP" job 10 times, and all 10 attempts passed. Each attempt ran the SCIM, stop-after and desktop inbox steps, every app started from an empty .next/dev, and stop-session.sh never reported a process outliving next dev. Healthy runs before the fix took 35–99s for the stop-after step. With a cold cache it takes about 75–115s.

vercel Bot deployed to Preview October 6, 2026 18:18 View deployment

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Comment thread apps/sim/scripts/test-workflow-stop-after-e2e.ts Outdated

waleedlatif1 force-pushed the fix/stop-after-e2e-cold-cache branch from 358b53b to 2c9bebe Compare October 6, 2026 18:26

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Comment thread .github/workflows/test-build.yml Outdated

waleedlatif1 added 4 commits October 6, 2026 12:42

fix(ci): start the desktop inbox app from an empty Turbopack dev cach…

1f3ea39

…e too

fix(e2e): record a status only for a fully read stop-after response

6583e33

fix(ci): stop each HTTP end-to-end app's whole process session before…

edc1d47

… the next one starts

waleedlatif1 force-pushed the fix/stop-after-e2e-cold-cache branch from cb75542 to edc1d47 Compare October 6, 2026 19:42

vercel Bot deployed to Preview October 6, 2026 19:46 View deployment

fix(e2e): compile the desktop executor routes before timing executor …

bd1e89d

…calls

vercel Bot temporarily deployed to Preview October 6, 2026 20:20 Inactive

waleedlatif1 changed the title ~~fix(ci): start each HTTP end-to-end app from an empty Turbopack dev cache~~ fix(ci): stop each HTTP end-to-end app fully and start the next from an empty dev cache Oct 6, 2026

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waleedlatif1 merged commit 11f8190 into staging Oct 6, 2026
277 of 278 checks passed

waleedlatif1 deleted the fix/stop-after-e2e-cold-cache branch October 6, 2026 22:29

waleedlatif1 mentioned this pull request Oct 6, 2026

fix(e2e): compile every timed route first in the HTTP suites and stop sessions completely #8701

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