Fix User Error in Async API Endpoint

[Timer]

Fixes #9463

[ijjk]

Stats from current PR

Default Server Mode

General Overall increase ⚠️

	zeit/next.js canary	Timer/next.js hotfix/async-api-errors	Change
buildDuration	12.8s	12.4s	-405ms
nodeModulesSize	48.9 MB	48.9 MB	⚠️ +12 B

Client Bundles (main, webpack, commons)

	zeit/next.js canary	Timer/next.js hotfix/async-api-errors	Change
main-HASH.js gzip	6.44 kB	6.44 kB	✓
webpack-HASH.js gzip	746 B	746 B	✓
4952ddcd88e7..54d3.js gzip	4.68 kB	4.68 kB	✓
commons.HASH.js gzip	4.06 kB	4.06 kB	✓
de003c3a9d30..6ef5.js gzip	13.8 kB	13.8 kB	✓
framework.HASH.js gzip	39.5 kB	39.5 kB	✓
Overall change	69.2 kB	69.2 kB	✓

Client Bundles (main, webpack, commons) Modern

	zeit/next.js canary	Timer/next.js hotfix/async-api-errors	Change
main-HASH.module.js gzip	5.42 kB	5.42 kB	✓
webpack-HASH..dule.js gzip	746 B	746 B	✓
4952ddcd88e7..dule.js gzip	5.56 kB	5.56 kB	✓
de003c3a9d30..dule.js gzip	12.6 kB	12.6 kB	✓
framework.HA..dule.js gzip	39.4 kB	39.4 kB	✓
Overall change	63.7 kB	63.7 kB	✓

Legacy Client Bundles (polyfills)

	zeit/next.js canary	Timer/next.js hotfix/async-api-errors	Change
polyfills-HASH.js gzip	4.76 kB	4.76 kB	✓
Overall change	4.76 kB	4.76 kB	✓

Client Pages

	zeit/next.js canary	Timer/next.js hotfix/async-api-errors	Change
_app.js gzip	1.33 kB	1.33 kB	✓
_error.js gzip	4.07 kB	4.07 kB	✓
hooks.js gzip	779 B	779 B	✓
index.js gzip	222 B	222 B	✓
link.js gzip	2.93 kB	2.93 kB	✓
routerDirect.js gzip	283 B	283 B	✓
withRouter.js gzip	282 B	282 B	✓
Overall change	9.89 kB	9.89 kB	✓

Client Pages Modern

	zeit/next.js canary	Timer/next.js hotfix/async-api-errors	Change
_app.module.js gzip	757 B	757 B	✓
_error.module.js gzip	3.06 kB	3.06 kB	✓
hooks.module.js gzip	371 B	371 B	✓
index.module.js gzip	212 B	212 B	✓
link.module.js gzip	2.49 kB	2.49 kB	✓
routerDirect..dule.js gzip	273 B	273 B	✓
withRouter.m..dule.js gzip	272 B	272 B	✓
Overall change	7.43 kB	7.43 kB	✓

Client Build Manifests

	zeit/next.js canary	Timer/next.js hotfix/async-api-errors	Change
_buildManifest.js gzip	61 B	61 B	✓
_buildManife..dule.js gzip	61 B	61 B	✓
Overall change	122 B	122 B	✓

Rendered Page Sizes

	zeit/next.js canary	Timer/next.js hotfix/async-api-errors	Change
index.html gzip	1.04 kB	1.04 kB	✓
link.html gzip	1.04 kB	1.04 kB	✓
withRouter.html gzip	1.03 kB	1.03 kB	✓
Overall change	3.12 kB	3.12 kB	✓

---

Serverless Mode

General Overall increase ⚠️

	zeit/next.js canary	Timer/next.js hotfix/async-api-errors	Change
buildDuration	13.1s	12.9s	-150ms
nodeModulesSize	48.9 MB	48.9 MB	⚠️ +12 B

Client Bundles (main, webpack, commons)

	zeit/next.js canary	Timer/next.js hotfix/async-api-errors	Change
main-HASH.js gzip	6.44 kB	6.44 kB	✓
webpack-HASH.js gzip	746 B	746 B	✓
4952ddcd88e7..54d3.js gzip	4.68 kB	4.68 kB	✓
commons.HASH.js gzip	4.06 kB	4.06 kB	✓
de003c3a9d30..6ef5.js gzip	13.8 kB	13.8 kB	✓
framework.HASH.js gzip	39.5 kB	39.5 kB	✓
Overall change	69.2 kB	69.2 kB	✓

Client Bundles (main, webpack, commons) Modern

	zeit/next.js canary	Timer/next.js hotfix/async-api-errors	Change
main-HASH.module.js gzip	5.42 kB	5.42 kB	✓
webpack-HASH..dule.js gzip	746 B	746 B	✓
4952ddcd88e7..dule.js gzip	5.56 kB	5.56 kB	✓
de003c3a9d30..dule.js gzip	12.6 kB	12.6 kB	✓
framework.HA..dule.js gzip	39.4 kB	39.4 kB	✓
Overall change	63.7 kB	63.7 kB	✓

Legacy Client Bundles (polyfills)

	zeit/next.js canary	Timer/next.js hotfix/async-api-errors	Change
polyfills-HASH.js gzip	4.76 kB	4.76 kB	✓
Overall change	4.76 kB	4.76 kB	✓

Client Pages

	zeit/next.js canary	Timer/next.js hotfix/async-api-errors	Change
_app.js gzip	1.33 kB	1.33 kB	✓
_error.js gzip	4.07 kB	4.07 kB	✓
hooks.js gzip	779 B	779 B	✓
index.js gzip	222 B	222 B	✓
link.js gzip	2.93 kB	2.93 kB	✓
routerDirect.js gzip	283 B	283 B	✓
withRouter.js gzip	282 B	282 B	✓
Overall change	9.89 kB	9.89 kB	✓

Client Pages Modern

	zeit/next.js canary	Timer/next.js hotfix/async-api-errors	Change
_app.module.js gzip	757 B	757 B	✓
_error.module.js gzip	3.06 kB	3.06 kB	✓
hooks.module.js gzip	371 B	371 B	✓
index.module.js gzip	212 B	212 B	✓
link.module.js gzip	2.49 kB	2.49 kB	✓
routerDirect..dule.js gzip	273 B	273 B	✓
withRouter.m..dule.js gzip	272 B	272 B	✓
Overall change	7.43 kB	7.43 kB	✓

Client Build Manifests

	zeit/next.js canary	Timer/next.js hotfix/async-api-errors	Change
_buildManifest.js gzip	61 B	61 B	✓
_buildManife..dule.js gzip	61 B	61 B	✓
Overall change	122 B	122 B	✓

Serverless bundles

	zeit/next.js canary	Timer/next.js hotfix/async-api-errors	Change
_error.js gzip	78.9 kB	78.9 kB	✓
hooks.html gzip	1.07 kB	1.07 kB	✓
index.js gzip	79.1 kB	79.1 kB	✓
link.js gzip	81.3 kB	81.3 kB	✓
routerDirect.js gzip	79.2 kB	79.2 kB	✓
withRouter.js gzip	79.3 kB	79.3 kB	✓
Overall change	399 kB	399 kB	✓

Commit: c8fb2f0