[fazxes]

Description

On Bun, initDataDir() throws for every new data directory:

ENOENT: no such file or directory, scandir '<dataDir>/events'

inspectEntityDirs() handles a missing events/ or steps/ directory by catching ENOENT from opendir(). Node rejects opendir() itself for a missing directory, but Bun resolves it and rejects on the first read, which happened outside the try. This change moves the read inside the same try, so a missing directory is skipped on both runtimes.

The bug came in with the per-run layout check in #4718 and is in @workflow/world-local 5.1.0. libfx hits it on Bun with local().

How did you test your changes?

• New src/init-lazy-opendir.test.ts mocks opendir() to behave as Bun's does and runs initDataDir() on a new directory and on one with only events/. Both cases fail without the fix with the ENOENT above, and pass with it.
• On Bun 1.3.12, initDataDir() from the built dist/init.js on a new directory: the original code fails with ENOENT ... scandir '<dataDir>/events', and the fixed build succeeds.
• vitest run src in packages/world-local: 27 files, 660 tests pass.
• biome check on the changed files and node scripts/check-changesets.mjs pass.

PR Checklist - Required to merge

• 📦 pnpm changeset was run to create a changelog for this PR
  • Use the correct semver bump type: patch for bug fixes, minor for new features, major for breaking changes.
  • Use pnpm changeset --empty if you are changing documentation or workbench apps
• 🔒 DCO sign-off passes (run git commit --signoff on your commits)
• 📝 Ping @vercel/workflow in a comment once the PR is ready, and the above checklist is complete

[changeset-bot]

🦋 Changeset detected

Latest commit: 95afa25

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 19 packages

Name	Type
@workflow/world-local	Patch
@workflow/cli	Patch
@workflow/core	Patch
@workflow/vitest	Patch
@workflow/web	Patch
@workflow/world-postgres	Patch
workflow	Patch
@workflow/world-testing	Patch
@workflow/builders	Patch
@workflow/next	Patch
@workflow/nitro	Patch
@workflow/web-shared	Patch
@workflow/astro	Patch
@workflow/nest	Patch
@workflow/rollup	Patch
@workflow/sveltekit	Patch
@workflow/vite	Patch
@workflow/nuxt	Patch
@workflow/world-vercel	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[github-actions]

📊 Workflow Benchmarks

commit 95afa25 · Mon, 12 Oct 2026 17:31:24 GMT · run logs

Backend: vercel · app: nextjs-turbopack

Metric	Scenario	Best (ms)	P75 (ms)	P90 (ms)	P99 (ms)	Samples
TTFS	step	263 (-11%)	1952 🔴 (+29%) 🔻	2181 🔴 (+32%) 🔻	2300 🔴 (+9.3%)	30
TTFS	stream	319 (+10%)	2236 🔴 (+54%) 🔻	2258 🔴 (+50%) 🔻	2272 🔴 (+40%) 🔻	30
TTFS	hook + stream	2093 (+30%) 🔻	2566 🔴 (+49%) 🔻	2653 🔴 (+52%) 🔻	2791 🔴 (+26%) 🔻	30
Fan-out TTFS	Promise.all(100 steps)	487 (+0.6%)	975 (+6.3%)	2391 (+152%) 🔻	2468 (+43%) 🔻	10
Fan-out TTLS	Promise.all(100 steps)	2665 (-25%) 💚	4345 (+2.8%)	5947 (+40%) 🔻	7826 (+80%) 🔻	10
STSO	1020 steps (inline)	72 (-15%) 💚	116 (+0.9%)	135 (-5.6%)	186 (-42%) 💚	1019
WO	1020 steps	116164 (±0%)	116164 (±0%)	116164 (±0%)	116164 (±0%)	1

📈 STSO distribution vs main (inline / queue-hop histograms)

1020 steps (inline)

Cumulative STSO time: main 115748ms → this run 115725ms (Δ -23ms, 0%)

 50-100 ms  ██┃████████               main 393  this 102  -291
100-150 ms  ███████████████░░░░░░░░┃  main 556  this 870  +314
150-200 ms  ┃                         main  48  this  40    -8
200-250 ms  ┃                         main   4  this   3    -1
250-300 ms  ┃                         main   5  this   2    -3
300-350 ms  ┃                         main   5  this   1    -4
350-400 ms  ┃                         main   2  this   0    -2
400-450 ms  ┃                         main   1  this   0    -1
450-500 ms  ┃                         main   1  this   0    -1
500-550 ms  ┃                         main   3  this   1    -2
550-600 ms  ┃                         main   1  this   0    -1

ℹ️ Metric definitions & methodology

_{The collapsed STSO distribution section above buckets every step gap, split inline (same warm process — pure framework overhead) vs queue-hop (fresh process — dispatch, reinit, replay). █ = main, ┃ = this run, ░ = fill.}

_{Best/P75/P90/P99 deltas compare against the most recent benchmark run on main at the time of this run. 🔻 flags a delta worse than +15%, 💚 one better than −15%.}

_{Metrics — TTFS: time to first step body (in-deployment start() → first step body) · Fan-out TTFS: fan-out time to first step (in-deployment start() → first of the parallel step bodies to complete) · Fan-out TTLS: fan-out time to last step (in-deployment start() → last of the parallel step bodies to complete, i.e. when the Promise.all resolves) · STSO: step-to-step overhead (gap between consecutive step bodies) · WO: workflow overhead (whole-run time outside step bodies, in-deployment anchored)}

_{Scenarios — step: one trivial no-op step, no stream; no hooks, so the run stays in turbo mode (in-process fast path) · stream: one streaming step; no hooks, so the run stays in turbo mode (in-process fast path) · hook + stream: registers a hook before one step, which exits turbo mode (dispatch path) · 1020 steps: 1020 trivial sequential steps; STSO is measured between consecutive steps in the given step ranges, and WO is the whole-run overhead outside step bodies · Promise.all(100 steps): 100 trivial no-op steps started together in a single Promise.all; Fan-out TTFS is the first of them to complete and Fan-out TTLS the last, both from the in-deployment clientStart, so their gap is the spread the runtime adds across the fan-out}

_{🔴 marks a percentile over its target (within target is left unmarked). Targets (p75/p90/p99, ms) — TTFS 200/300/600}

_{All timestamps are deployment-side; runs are triggered in-deployment, so the CI runner and api.vercel.com sit outside every measured window. TTFS = start() → first step body (includes dispatch + any cold start); Fan-out TTFS/TTLS = first/last step completion of one Promise.all from the same anchor (the gap is the runtime’s fan-out spread); STSO/WO between step bodies. Streaming delivery performance is measured in durabench.}

_{Cold starts stay in the numbers (real bursty-workload latency, inflates P75+); Best is the warm floor.}

[github-actions]

🧪 E2E Test Results

✅ All tests passed

⚠️ Flaky E2E Tests (passed on retry)

These tests failed at least once and passed on a retry. A recurring entry here is a real race worth investigating.

• health check (CLI) - workflow health command reports healthy endpoints (nuxt · local-dev / local / node / stable)

🛠 Infra Events (absorbed by the harness)

Platform anomalies the e2e harness detected and worked around (e.g. a run the queue never picked up, replaced by a fresh run). Clustered timestamps indicate a backend blip; a steady drip indicates a platform issue worth escalating.

• run-pickup-stall · hookCleanupTestWorkflow - hook token reuse after workflow completion (nextjs-webpack) · at 17:27:07Z · abandoned wrun_01M4RJEAJY0P831FDYRS7SZZNR

E2E Test Summary

Summary

	Passed	Failed	Skipped	Total
✅ ▲ Vercel Production	3982	0	878	4860
✅ 💻 Local Development	4669	0	551	5220
✅ 📦 Local Production	4669	0	551	5220
✅ 🐘 Local Postgres	4669	0	551	5220
✅ 🪟 Windows	348	0	12	360
✅ 🌐 Cross-language Conformance	68	0	87	155
✅ dynamic-runs	0	0	0	0
✅ vercel-http-transport	897	0	183	1080
✅ vercel-multi-region	27	0	0	27
✅ vercel-ws-transport	607	0	113	720
Total	19936	0	2926	22862

Details by Category

✅ ▲ Vercel Production

App	Passed	Failed	Skipped
✅ astro-node	145	0	35
✅ astro-quickjs	145	0	35
✅ example-node	145	0	35
✅ example-quickjs	145	0	35
✅ express-node	145	0	35
✅ express-quickjs	145	0	35
✅ fastify-node	145	0	35
✅ fastify-quickjs	145	0	35
✅ hono-node	145	0	35
✅ hono-quickjs	145	0	35
✅ nest-node	145	0	35
✅ nest-quickjs	145	0	35
✅ nextjs-turbopack-node	172	0	8
✅ nextjs-turbopack-quickjs	172	0	8
✅ nextjs-webpack-node	172	0	8
✅ nextjs-webpack-quickjs	172	0	8
✅ nitro-node	145	0	35
✅ nitro-quickjs	145	0	35
✅ nuxt-node	145	0	35
✅ nuxt-quickjs	145	0	35
✅ python-node	66	0	114
✅ sveltekit-node	164	0	16
✅ sveltekit-quickjs	164	0	16
✅ tanstack-start-node	145	0	35
✅ tanstack-start-quickjs	145	0	35
✅ vite-node	145	0	35
✅ vite-quickjs	145	0	35

✅ 💻 Local Development

App	Passed	Failed	Skipped
✅ astro-stable-node	151	0	29
✅ astro-stable-quickjs	151	0	29
✅ express-stable-node	151	0	29
✅ express-stable-quickjs	151	0	29
✅ fastify-stable-node	151	0	29
✅ fastify-stable-quickjs	151	0	29
✅ hono-stable-node	151	0	29
✅ hono-stable-quickjs	151	0	29
✅ nest-stable-node	151	0	29
✅ nest-stable-quickjs	151	0	29
✅ nextjs-turbopack-canary-node	179	0	1
✅ nextjs-turbopack-canary-quickjs	179	0	1
✅ nextjs-turbopack-quickjs-snapshot	179	0	1
✅ nextjs-turbopack-stable-node	179	0	1
✅ nextjs-turbopack-stable-quickjs	179	0	1
✅ nextjs-webpack-canary-node	179	0	1
✅ nextjs-webpack-canary-quickjs	179	0	1
✅ nextjs-webpack-stable-node	179	0	1
✅ nextjs-webpack-stable-quickjs	179	0	1
✅ nitro-stable-node	151	0	29
✅ nitro-stable-quickjs	151	0	29
✅ nuxt-stable-node	151	0	29
✅ nuxt-stable-quickjs	151	0	29
✅ sveltekit-stable-node	170	0	10
✅ sveltekit-stable-quickjs	170	0	10
✅ tanstack-start-node	151	0	29
✅ tanstack-start-quickjs	151	0	29
✅ vite-stable-node	151	0	29
✅ vite-stable-quickjs	151	0	29

✅ 📦 Local Production

App	Passed	Failed	Skipped
✅ astro-stable-node	151	0	29
✅ astro-stable-quickjs	151	0	29
✅ express-stable-node	151	0	29
✅ express-stable-quickjs	151	0	29
✅ fastify-stable-node	151	0	29
✅ fastify-stable-quickjs	151	0	29
✅ hono-stable-node	151	0	29
✅ hono-stable-quickjs	151	0	29
✅ nest-stable-node	151	0	29
✅ nest-stable-quickjs	151	0	29
✅ nextjs-turbopack-canary-node	179	0	1
✅ nextjs-turbopack-canary-quickjs	179	0	1
✅ nextjs-turbopack-quickjs-snapshot	179	0	1
✅ nextjs-turbopack-stable-node	179	0	1
✅ nextjs-turbopack-stable-quickjs	179	0	1
✅ nextjs-webpack-canary-node	179	0	1
✅ nextjs-webpack-canary-quickjs	179	0	1
✅ nextjs-webpack-stable-node	179	0	1
✅ nextjs-webpack-stable-quickjs	179	0	1
✅ nitro-stable-node	151	0	29
✅ nitro-stable-quickjs	151	0	29
✅ nuxt-stable-node	151	0	29
✅ nuxt-stable-quickjs	151	0	29
✅ sveltekit-stable-node	170	0	10
✅ sveltekit-stable-quickjs	170	0	10
✅ tanstack-start-node	151	0	29
✅ tanstack-start-quickjs	151	0	29
✅ vite-stable-node	151	0	29
✅ vite-stable-quickjs	151	0	29

✅ 🐘 Local Postgres

App	Passed	Failed	Skipped
✅ astro-stable-node	151	0	29
✅ astro-stable-quickjs	151	0	29
✅ express-stable-node	151	0	29
✅ express-stable-quickjs	151	0	29
✅ fastify-stable-node	151	0	29
✅ fastify-stable-quickjs	151	0	29
✅ hono-stable-node	151	0	29
✅ hono-stable-quickjs	151	0	29
✅ nest-stable-node	151	0	29
✅ nest-stable-quickjs	151	0	29
✅ nextjs-turbopack-canary-node	179	0	1
✅ nextjs-turbopack-canary-quickjs	179	0	1
✅ nextjs-turbopack-quickjs-snapshot	179	0	1
✅ nextjs-turbopack-stable-node	179	0	1
✅ nextjs-turbopack-stable-quickjs	179	0	1
✅ nextjs-webpack-canary-node	179	0	1
✅ nextjs-webpack-canary-quickjs	179	0	1
✅ nextjs-webpack-stable-node	179	0	1
✅ nextjs-webpack-stable-quickjs	179	0	1
✅ nitro-stable-node	151	0	29
✅ nitro-stable-quickjs	151	0	29
✅ nuxt-stable-node	151	0	29
✅ nuxt-stable-quickjs	151	0	29
✅ sveltekit-stable-node	170	0	10
✅ sveltekit-stable-quickjs	170	0	10
✅ tanstack-start-node	151	0	29
✅ tanstack-start-quickjs	151	0	29
✅ vite-stable-node	151	0	29
✅ vite-stable-quickjs	151	0	29

✅ 🪟 Windows

App	Passed	Failed	Skipped
✅ nextjs-turbopack-node	174	0	6
✅ nextjs-turbopack-quickjs	174	0	6

✅ 🌐 Cross-language Conformance

App	Passed	Failed	Skipped
✅ python	68	0	87

✅ dynamic-runs

App	Passed	Failed	Skipped
✅ astro-vercel	0	0	0
✅ example-vercel	0	0	0
✅ express-vercel	0	0	0
✅ fastify-vercel	0	0	0
✅ hono-vercel	0	0	0
✅ nest-vercel	0	0	0
✅ nextjs-turbopack-vercel	0	0	0
✅ nextjs-webpack-vercel	0	0	0
✅ nitro-vercel	0	0	0
✅ nuxt-vercel	0	0	0
✅ sveltekit-vercel	0	0	0
✅ tanstack-start-vercel	0	0	0
✅ vite-vercel	0	0	0

✅ vercel-http-transport

App	Passed	Failed	Skipped
✅ example	145	0	35
✅ express	145	0	35
✅ hono	145	0	35
✅ nextjs-turbopack	172	0	8
✅ nitro	145	0	35
✅ vite	145	0	35

✅ vercel-multi-region

App	Passed	Failed	Skipped
✅ nextjs-turbopack	27	0	0

✅ vercel-ws-transport

App	Passed	Failed	Skipped
✅ example	145	0	35
✅ express	145	0	35
✅ nextjs-turbopack	172	0	8
✅ vite	145	0	35

---

📋 View full workflow run

[github-actions]

Sim World

Simulated world deterministic testing for races. Traces

🟢 world-sim scenario book — 0 fail of 42 total

fence=per-spec

scenario	outcome	events	virt	replay	violations
✅ smoke-no-steps	completed	3	0ms	ok	0
✅ smoke-one-step	completed	6	0ms	ok	0
✅ hook-at-step-started	completed	12	0ms	ok	0
✅ hook-at-step-completed	completed	12	0ms	ok	0
✅ hook-at-hook-created	completed	12	0ms	ok	0
✅ deadline-hook-wins	completed	7	1.0h	ok	0
✅ deadline-expires	completed	7	1.0h	ok	0
✅ step-vs-timer-early-settlement	completed	8	1.0h	ok	0
✅ long-sleep	completed	11	30.0d	ok	0
✅ hook-never-arrives	stalled	3	0ms	skipped	0
✅ step-retries-twice	completed	10	2.0s	ok	0
✅ parallel-steps	completed	9	0ms	ok	0
✅ hook-on-execution-state	completed	12	0ms	ok	0
✅ peek-hook-before-branch	completed	12	0ms	ok	0
✅ peek-hook-after-branch	completed	12	0ms	ok	0
✅ peek-hook-at-registration	completed	12	0ms	ok	0
✅ race-hook-before-probe	completed	12	0ms	ok	0
✅ race-hook-after-probe	completed	12	0ms	ok	0
✅ race-duplicate-delivery	completed	13	0ms	ok	0
✅ attr-hook-before-step	completed	11	0ms	ok	0
✅ attr-hook-after-step	completed	11	0ms	ok	0
✅ attr-from-step-body	completed	13	0ms	ok	0
✅ fork-hook-after-timeout	completed	14	1.0m	ok	0
✅ fork-hook-before-timeout	completed	14	1.0m	ok	0
✅ count-hook-after-timeout	completed	17	1.0m	ok	0
✅ count-hook-before-timeout	completed	20	1.0m	ok	0
✅ stale-read-step-count-fork	completed	20	1.0m	ok	0
✅ stale-read-equal-step-counts	completed	14	1.0m	ok	0
✅ step-vs-step-fork	completed	12	0ms	ok	0
✅ step-vs-step-fork-fenced	completed	12	0ms	ok	0
✅ fence-catches-benign-direction	completed	12	5ms	ok	0
✅ in-flight-before-decision	completed	17	1.0m	ok	0
✅ in-flight-before-decision-counted	completed	17	1.0m	ok	0
✅ in-flight-after-decision	completed	19	2.0m	ok	0
✅ stale-read-step-count-fork-fenced	completed	20	1.0m	ok	0
✅ fork-hook-wins	completed	13	1.0m	ok	0
✅ fork-timeout-wins	completed	13	1.0m	ok	0
✅ unclaimed-payload-under-fork	completed	17	1.0m	ok	0
✅ claimed-payload-under-fork	completed	17	1.0m	ok	0
✅ writers-independent-step-bodies	completed	12	0ms	ok	0
✅ writers-scripted-tempo	completed	12	0ms	ok	0
✅ cancel-mid-step	cancelled	7	0ms	skipped	0

Full trace: world-sim.txt

[github-actions]

Framework	Flow route	Step reg.	Framework output
hono	267.4 KiB (±0)	95.4 KiB (±0)	1.99 MiB (-12 B)
nextjs-turbopack	274.8 KiB (±0)	426 B (±0)	969.9 KiB (-2 B)

About these numbers

Sizes are gzip; parentheses show the change against main.
Flow route and Step reg. gate this job, on raw bytes rather than the gzip shown, at max(2%, 50.0 KiB). Framework output is informational.

95afa25 · run

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated
example-nextjs-workflow-turbopack	Ready	Preview, v0	Oct 12, 2026 6:14pm UTC
example-nextjs-workflow-webpack	Ready	Preview, v0	Oct 12, 2026 6:14pm UTC
example-workflow	Ready	Preview, v0	Oct 12, 2026 6:14pm UTC
workbench-astro-workflow	Ready	Preview, v0	Oct 12, 2026 6:14pm UTC
workbench-express-workflow	Ready	Preview, v0	Oct 12, 2026 6:14pm UTC
workbench-fastify-workflow	Ready	Preview, v0	Oct 12, 2026 6:14pm UTC
workbench-hono-workflow	Ready	Preview, v0	Oct 12, 2026 6:14pm UTC
workbench-nestjs-workflow	Ready	Preview, v0	Oct 12, 2026 6:14pm UTC
workbench-nitro-workflow	Ready	Preview, v0	Oct 12, 2026 6:14pm UTC
workbench-nuxt-workflow	Ready	Preview, v0	Oct 12, 2026 6:14pm UTC
workbench-python-workflow	Ready	Preview, v0	Oct 12, 2026 6:14pm UTC
workbench-sveltekit-workflow	Ready	Preview, v0	Oct 12, 2026 6:14pm UTC
workbench-tanstack-start-workflow	Ready	Preview, v0	Oct 12, 2026 6:14pm UTC
workbench-vite-workflow	Ready	Preview, v0	Oct 12, 2026 6:14pm UTC
workflow-docs	Ready	Preview, v0	Oct 12, 2026 6:14pm UTC
workflow-swc-playground	Ready	Preview, v0	Oct 12, 2026 6:14pm UTC
workflow-tarballs	Ready	Preview, v0	Oct 12, 2026 6:14pm UTC
workflow-web	Ready	Preview, v0	Oct 12, 2026 6:14pm UTC

[pranaygp]

Summary. Moves the for await read of each entity directory inside the try that handles ENOENT in inspectEntityDirs(). On Bun 1.3.x, opendir() succeeds for a missing path and the error shows up on the first read. I reproduced it with the built dist/init.js under Bun 1.3.12: main fails for every new or partial data directory, and this branch fixes it.

Upstream. This is a Bun bug, tracked as oven-sh/bun#17581 ("opendirSync successfully returns for a non-existent directory"). It was fixed by oven-sh/bun#31830, which first shipped in Bun 1.4.0. I checked: Bun 1.3.12 and 1.3.14 reject on the first read (syscall: scandir), while 1.4.0 and 1.4.3 reject at opendir() like Node. The main build of world-local already works on Bun ≥ 1.4.0. This PR is still worth merging for anyone on Bun 1.3.x, and the new structure is correct on both runtimes. Consider mentioning the Bun issue and the 1.4.0 fix in the code comment so this can be revisited once 1.3.x support is dropped.

Correctness. I found no bugs. I ran initDataDir() over all 81 combinations of 9 states for events/ and steps/ (missing, empty, run dirs, flat file, unknown .json, mixed, non-JSON only, a file in place of the dir, mode 000). Node on main, Node on this branch and Bun 1.3.12 on this branch give identical results in every case, including whether version.txt gets written. Errors other than ENOENT (such as ENOTDIR) still propagate on both runtimes. Reverting init.ts makes both new tests fail with the reported ENOENT. vitest run src in packages/world-local passes.

Risks / missing tests (none blocking)

1. packages/world-local/src/init.ts:361-368: the catch now also covers errors thrown while iterating. An ENOENT partway through would continue with a partly filled layout where it used to throw. I don't think either runtime can reach this: Bun 1.3.x fails on the first read, before any entries arrive, and on Linux reading a directory that was removed while open just ends the listing. The steady-state result is unchanged.
2. Nothing in CI runs world-local on Bun, and that gap let #4718 ship this regression. The mock-based test is a good guard for this particular behaviour. A small follow-up job (setup-bun + initDataDir() on a temp directory) would catch the next difference between the runtimes.
3. init-lazy-opendir.test.ts: the mock iterator has no return()/close(). That's fine today, because a rejected next() doesn't trigger return(), but the mock will break if the code ever calls dir.close() explicitly.

Observability / security / performance / docs. No logging or telemetry changes. On Bun 1.3.x the error now reports syscall: 'scandir' rather than 'opendir', which only matters to log searches that key on it. No security impact: same paths, no symlink handling change, and rm still only runs after the same classification. Performance is unchanged (one opendir per entity dir). The patch changeset is correctly scoped.

Nits

• init.ts:359: the comment could say "rejects on the first read (Bun < 1.4) rather than at opendir() (Node)" and link oven-sh/bun#17581.

LGTM, approving.

[github-actions]

No backport to stable for b69fabe (AI decision).

This fixes inspectEntityDirs() in packages/world-local/src/init.ts, code introduced by the per-run layout check in #4718 and shipped in @workflow/world-local 5.1.0. I verified that origin/stable's copy of that file (world-local 4.4.3) contains no inspectEntityDirs, no opendir call, and no RUN_SCOPED_ENTITY_DIRS, so the defect does not exist on the maintenance line and the fix (plus its new test) has nothing to apply to.

To override, re-run the Backport to stable workflow manually via workflow_dispatch and paste this commit SHA into the ref input:

b69fabecf21cdd61bd411dc7c81db67c704583ae