now.json breaks Vercel Deployment

Issue: I just realized that my nuxt apps have really poor Lighthouse metrics when I deploy them on vercel and from time to time, I am unable to visit the Site completely because of a 502 Bad gateway error. When I dug into this and searched for the source of this bad performance I realized that a freshly created nuxt app works like a charm. The issues start, as soon as I add the now.json from the offical Nuxt documentation.

Example project: https://github.com/thmsnhl/frenimals An example branch with now.json (502 Error): https://frenimals-git-feat-now-json.thmsnhl-voll.vercel.app/ An example branch without now.json: https://frenimals-git-feat-no-now-json.thmsnhl-voll.vercel.app/

Build logs

17:49:09.663  	Installing build runtime...
17:49:13.586  	Build runtime installed: 3923.155ms
17:49:14.252  	Looking up build cache...
17:49:14.592  	Build cache not found
17:49:15.243  	Running with @nuxt/vercel-builder version 0.18.0
17:49:15.244  	 ----------------- Prepare build ----------------- 
17:49:15.244  	Downloading files...
17:49:15.245  	Working directory: /vercel/workpath0
17:49:15.257  	Using yarn
17:49:15.263  	ℹ Prepare build took: 18.516535 ms
17:49:15.263  	 ----------------- Install devDependencies ----------------- 
17:49:15.568  	yarn install v1.22.4
17:49:15.675  	[1/5] Resolving packages...
17:49:16.371  	[2/5] Fetching packages...
17:49:36.161  	info fsevents@2.1.3: The platform "linux" is incompatible with this module.
17:49:36.161  	info "fsevents@2.1.3" is an optional dependency and failed compatibility check. Excluding it from installation.
17:49:36.177  	info fsevents@1.2.13: The platform "linux" is incompatible with this module.
17:49:36.177  	info "fsevents@1.2.13" is an optional dependency and failed compatibility check. Excluding it from installation.
17:49:36.183  	[3/5] Linking dependencies...
17:49:36.186  	warning "nuxt > @nuxt/components@1.1.1" has unmet peer dependency "webpack@^4.0.0".
17:49:36.196  	warning "@nuxtjs/eslint-config > eslint-plugin-vue@6.2.2" has incorrect peer dependency "eslint@^5.0.0 || ^6.0.0".
17:49:36.196  	warning "@nuxtjs/eslint-config > eslint-plugin-jest > @typescript-eslint/experimental-utils > @typescript-eslint/typescript-estree > tsutils@3.17.1" has unmet peer dependency "typescript@>=2.8.0 || >= 3.2.0-dev || >= 3.3.0-dev || >= 3.4.0-dev || >= 3.5.0-dev || >= 3.6.0-dev || >= 3.6.0-beta || >= 3.7.0-dev || >= 3.7.0-beta".
17:49:36.196  	warning "@nuxtjs/eslint-module > eslint-loader@4.0.2" has unmet peer dependency "webpack@^4.0.0 || ^5.0.0".
17:49:36.197  	warning "@nuxtjs/stylelint-module > stylelint-webpack-plugin@2.1.1" has unmet peer dependency "webpack@^4.0.0 || ^5.0.0".
17:49:47.022  	[4/5] Building fresh packages...
17:49:48.269  	[5/5] Cleaning modules...
17:49:52.138  	Done in 36.58s.
17:49:52.167  	ℹ Install devDependencies took: 36902.785469 ms
17:49:52.167  	 ----------------- Nuxt build ----------------- 
17:49:52.202  	Running nuxt build --standalone --no-lock --config-file "nuxt.config.js"
17:49:55.131  	 WARN  [remark-footnotes] Warning: please upgrade to remark 13 to use this plugin
17:49:55.170  	ℹ Parsed 1 files in 0,9 seconds
17:50:02.310  	ℹ Production build
17:50:02.311  	ℹ Bundling for server and client side
17:50:02.311  	ℹ Target: static
17:50:02.338  	✔ Builder initialized
17:50:02.391  	✔ Nuxt files generated
17:50:04.959  	ℹ Compiling Client
17:50:09.186  	 WARN 
17:50:09.186  	 WARN  warn - The conservative purge mode will be removed in Tailwind 2.0.
17:50:09.186  	 WARN  warn - Please switch to the new layers mode instead.
17:50:18.933  	✔ Client: Compiled successfully in 13.97s
17:50:18.940  	ℹ Compiling Server
17:50:22.666  	✔ Server: Compiled successfully in 3.73s
17:50:22.668  	Hash: f21cbb7b38a3c8feea96
17:50:22.668  	Version: webpack 4.44.2
17:50:22.668  	Time: 13976ms
17:50:22.668  	Built at: 11/17/2020 4:50:18 PM
17:50:22.668  	                         Asset       Size  Chunks                                Chunk Names
17:50:22.668  	../server/client.manifest.json   10.5 KiB          [emitted]                     
17:50:22.668  	                    5043383.js   2.95 KiB       2  [emitted] [immutable]         pages/index
17:50:22.668  	                    79bf195.js   4.43 KiB       4  [emitted] [immutable]         
17:50:22.668  	                      LICENSES  318 bytes          [emitted]                     
17:50:22.668  	                    c60e772.js   2.32 KiB       3  [emitted] [immutable]         runtime
17:50:22.668  	                    db7fed0.js    285 KiB       0  [emitted] [immutable]  [big]  app
17:50:22.668  	                    fd08894.js   98.8 KiB       1  [emitted] [immutable]         content/plugin.js
17:50:22.668  	 + 2 hidden assets
17:50:22.668  	Entrypoint app = c60e772.js db7fed0.js
17:50:22.668  	WARNING in asset size limit: The following asset(s) exceed the recommended size limit (244 KiB).
17:50:22.669  	This can impact web performance.
17:50:22.669  	Assets: 
17:50:22.669  	  db7fed0.js (285 KiB)
17:50:22.669  	Hash: 4aa67d7f1cf64301cd2e
17:50:22.669  	Version: webpack 4.44.2
17:50:22.669  	Time: 3728ms
17:50:22.669  	Built at: 11/17/2020 4:50:22 PM
17:50:22.669  	               Asset       Size  Chunks             Chunk Names
17:50:22.669  	      pages/index.js   11.6 KiB       1  [emitted]  pages/index
17:50:22.669  	           server.js    472 KiB       0  [emitted]  app
17:50:22.669  	server.manifest.json  207 bytes          [emitted]  
17:50:22.669  	 + 2 hidden assets
17:50:22.669  	Entrypoint app = server.js server.js.map
17:50:22.677  	ℹ Ready to run nuxt generate
17:50:26.747  	ℹ Nuxt build took: 34579.09299 ms
17:50:26.747  	 ----------------- Install dependencies ----------------- 
17:50:27.055  	yarn install v1.22.4
17:50:27.167  	[1/5] Resolving packages...
17:50:28.160  	[2/5] Fetching packages...
17:50:28.329  	info fsevents@2.1.3: The platform "linux" is incompatible with this module.
17:50:28.329  	info "fsevents@2.1.3" is an optional dependency and failed compatibility check. Excluding it from installation.
17:50:28.337  	[3/5] Linking dependencies...
17:50:30.671  	[4/5] Building fresh packages...
17:50:31.009  	[5/5] Cleaning modules...
17:50:31.868  	Done in 4.82s.
17:50:31.890  	ℹ Install dependencies took: 5142.970839 ms
17:50:31.890  	 ----------------- Collect artifacts ----------------- 
17:50:37.705  	ℹ Collect artifacts took: 5810.716694 ms
17:50:38.513  	Uploading build outputs...
17:50:44.929  	Build completed. Populating build cache...
17:50:45.255  	 ----------------- Collect cache ----------------- 
17:50:54.500  	ℹ 68 files collected from .nuxt
17:51:06.084  	ℹ 30543 files collected from .vercel_cache
17:51:17.007  	ℹ 27313 files collected from node_modules_dev
17:51:26.698  	ℹ 6760 files collected from node_modules_prod
17:51:26.703  	ℹ Collect cache took: 41448.569059 ms
17:51:56.185  	Uploading build cache [79.48 MB]...
17:52:00.508  	Build cache uploaded: 4322.109ms
17:52:00.532  	Done with "nuxt.config.js"

Error Logs

[GET] /
18:08:33:61
 FATAL  ENOENT: no such file or directory, mkdir '/var/task/.nuxt/dist/client'
2020-11-17T17:08:33.905Z	d0281e6a-999a-4805-b8df-3515e68b9e25	ERROR	Unhandled Promise Rejection 	{"errorType":"Runtime.UnhandledPromiseRejection","errorMessage":"Error: ENOENT: no such file or directory, open '/var/task/static/sw.js'","reason":{"errorType":"Error","errorMessage":"ENOENT: no such file or directory, open '/var/task/static/sw.js'","code":"ENOENT","errno":-2,"syscall":"open","path":"/var/task/static/sw.js","stack":["Error: ENOENT: no such file or directory, open '/var/task/static/sw.js'"]},"promise":{},"stack":["Runtime.UnhandledPromiseRejection: Error: ENOENT: no such file or directory, open '/var/task/static/sw.js'","    at process.<anonymous> (/var/runtime/index.js:35:15)","    at process.emit (events.js:327:22)","    at process.EventEmitter.emit (domain.js:483:12)","    at processEmit [as emit] (/var/task/node_modules/signal-exit/index.js:161:32)","    at processPromiseRejections (internal/process/promises.js:209:33)","    at processTicksAndRejections (internal/process/task_queues.js:98:32)"]}
Unknown application error occurred

Just let me know if there is anything else, that I can post here to make it easier to debug.

[thmsnhl]

@danielroe sorry that it took me so long to come back to this. I adjusted the configuration to target: 'server' and was not able to reproduce the issues I had in the other project.

However, it would be nice to have an error message pointing out that now.json should only be used with target: 'server' if current target is set to 'static'.

Thanks again for helping me out and for your patience!

[thmsnhl]

@danielroe thank you for reaching out and for clarifying this. I switched to a static target because the page load of an other site (target: 'server') took more than 15 seconds before the first byte.

I will try to recreate this effect tomorrow and close/update this issue if necessary.