fix(dev): disable dev channels when BroadcastChannel throws

[danielroe]

🔗 Linked issue

nuxt/nuxt#36469

📚 Description

this disables use of global BroadcastChannel if it's unavailable (eg stackblitz)

[pkg-pr-new]

• nuxt-cli-playground

  npm i https://pkg.pr.new/create-nuxt@1600
  

  npm i https://pkg.pr.new/nuxi@1600
  

  npm i https://pkg.pr.new/@nuxt/cli@1600
  

commit: f6f4714

[github-actions]

CLI benchmark

@nuxt/cli v4.0.0 (baseline) vs v4.0.0 (this PR)

Metric	baseline v4.0.0	head v4.0.0	Delta
nuxt --version wall time (median)	66 ms	66 ms	+0.1%
nuxt --help wall time (median)	143 ms	144 ms	+0.5%
nuxt dev --help wall time (median)	110 ms	108 ms	-2.4%
nuxt --version modules loaded	35	35	0.0%
nuxt --version built-ins loaded	27	27	0.0%
nuxt --help modules loaded	135	135	0.0%
nuxt --help built-ins loaded	87	87	0.0%
nuxt dev --help modules loaded	64	64	0.0%
nuxt dev --help built-ins loaded	87	87	0.0%
Installed node_modules	2.46 MB	2.46 MB	+0.0%
Published tarball (packed)	240.2 kB	240.3 kB	+0.1%

Full report

@nuxt/cli v4.0.0 (baseline) vs v4.0.0 (head)

Setting	Value
Baseline	ref:c3abf230966a9063ccde0a3024e0508bcaf75bb4 (v4.0.0)
Head	local packages/nuxt-cli at c1a3646 (v4.0.0)
Node	v24.21.0
OS	Linux 6.17.0 (kernel 6.17.0-1022-azure)
CPU	AMD EPYC 7763 64-Core Processor x 4
Memory	15.6 GB
Load average at start	1.01, 0.32, 0.11
Run started	2026-10-06T12:30:02.087Z

Cold CLI startup

Median of 15 interleaved runs per command, one warmup discarded.

Command	baseline v4.0.0 median	head v4.0.0 median	Delta	baseline v4.0.0 min / p95	head v4.0.0 min / p95
nuxt --version	66 ms	66 ms	+0.1%	65 ms / 71 ms	65 ms / 70 ms
nuxt --version (first output byte)	62 ms	62 ms	-0.0%	60 ms / 67 ms	60 ms / 65 ms
nuxt --help	143 ms	144 ms	+0.5%	140 ms / 149 ms	136 ms / 149 ms
nuxt --help (first output byte)	137 ms	138 ms	+0.4%	134 ms / 144 ms	131 ms / 143 ms
nuxt dev --help	110 ms	108 ms	-2.4%	101 ms / 114 ms	101 ms / 111 ms
nuxt dev --help (first output byte)	105 ms	102 ms	-2.6%	96 ms / 108 ms	96 ms / 106 ms
nuxt <unknown-command> (no-op)	153 ms	153 ms	-0.5%	147 ms / 157 ms	151 ms / 163 ms
nuxt <unknown-command> (no-op) (first output byte)	147 ms	147 ms	-0.3%	141 ms / 151 ms	145 ms / 157 ms

Module load cost

Counted with a module.registerHooks load hook, compile cache disabled. Counts every JS module actually evaluated on that code path (native addons excluded). Built-ins loaded after bootstrap are counted separately, including the internal modules they load.

Command	baseline v4.0.0 modules	head v4.0.0 modules	Delta	baseline v4.0.0 source bytes	head v4.0.0 source bytes	Delta	baseline v4.0.0 built-ins	head v4.0.0 built-ins	Delta
nuxt --version	35	35	0.0%	297.8 kB	297.8 kB	0.0%	27	27	0.0%
nuxt --help	135	135	0.0%	847.1 kB	847.1 kB	0.0%	87	87	0.0%
nuxt dev --help	64	64	0.0%	455.3 kB	455.3 kB	0.0%	87	87	0.0%

Install footprint and published tarball

Each version installed on its own into an empty project with nothing but @nuxt/cli as a dependency, so the tree is exactly the CLI and its transitive dependencies. npm cache is warm and the registry is only consulted for metadata, so install wall time is indicative, not a network benchmark.

Metric	baseline v4.0.0	head v4.0.0	Delta
Direct dependencies of @nuxt/cli	23	23	0.0%
Packages in the installed tree (unique name@version)	39	39	0.0%
Unique package names	39	39	0.0%
Package directories on disk (cross-check)	32	32	0.0%
Installed node_modules on disk	2.46 MB	2.46 MB	+0.0%
Installed files	435	436	+0.2%
Install wall time (warm npm cache, median of 3)	1.34 s	1.33 s	-0.6%
Published tarball (packed)	240.2 kB	240.3 kB	+0.1%
Published tarball (unpacked)	780.0 kB	780.3 kB	+0.0%
Files in tarball	100	101	+1.0%

Interleaved runs on a shared runner: trust the deltas, not the absolute timings. The dev, restart and build suites run locally via pnpm bench:cli.

[codspeed]

Merging this PR will not alter performance

✅ 2 untouched benchmarks

---

_{Comparing fix/stackblitz-log-channel (f6f4714) with main (eec52f0)¹}

Footnotes

1. No successful run was found on main (c3abf23) during the generation of this report, so eec52f0 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

• Configuration used: Organization UI
• Review profile: CHILL
• Plan: Advanced
• Run ID: 2ab69370-a1da-4f53-986d-1258c2f00d70

📥 Commits

Reviewing files that changed from the base of the PR and between 7b7e52e and f6f4714.

📒 Files selected for processing (2)

• packages/nuxt-cli/src/dev/broadcast.ts
• packages/nuxt-cli/test/unit/broadcast.spec.ts

Included review availability: This review used your included allowance. Your plan provides up to 2 included reviews per hour; 1 remain after this review.

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📝 Walkthrough

Walkthrough

The development error, log, and span channels now use a shared helper to open broadcast channels and handle setup failures. The nuxt add, create nuxt, and nuxt module add documentation now lists upm as a package-manager option. Captured Nuxt development output shows updated style hashes and version-transition banners.

Priority: ➖ Normal

Estimated code review effort: 3 (Moderate) | ~20 minutes

Merge Risk: ⚪ Minimal · up to f6f47

No confirmed merge-blocking issue remains. The change can proceed with normal checks.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	Docstring coverage is 80.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 5 functions across 5 files.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly summarizes the change: dev channels are disabled when BroadcastChannel setup throws.
Description check	✅ Passed	The description identifies the BroadcastChannel availability issue that this change addresses.

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