`ng build` stuck in a SSG + Zoneless app

[javiermarinros]

Command

build

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

No response

Description

I'm trying to build an SSG and Zoneless site using the latest version of Angular, 19, as well as the new SSR rendering APIs.

However, the process gets stuck indefinitely, without providing any clue as to what might be happening, not even when running it with the --verbose flag.

The development server is working as intended. It respects the server routes configuration, providing some routes as pre-rendered and others to be rendered on the client.

Minimal Reproduction

I’m sorry I can’t provide more information or steps to reproduce it, but I’m completely out of leads 😅

I’d be happy to share more information if there's a way to provide additional details to the ng build command beyond using the verbose flag.

Exception or Error

ng build --verbose
⠙ Building...

  polyfills.server.mjs  265.3kb

⠼ Building...

  polyfills-LDJZCKZE.js  3.0kb

⠴ Building...
● [DEBUG] This case clause will never be evaluated because it duplicates an earlier case clause [duplicate-case]

    node_modules/firebaseui/dist/esm.js:4861:8:
      4861 │         case 224:
           ╵         ~~~~

  The earlier case clause is here:

    node_modules/firebaseui/dist/esm.js:4847:8:
      4847 │         case 224:
           ╵         ~~~~

● [DEBUG] This case clause will never be evaluated because it duplicates an earlier case clause [duplicate-case]

    node_modules/firebaseui/dist/esm.js:4890:8:
      4890 │         case 192:
           ╵         ~~~~

  The earlier case clause is here:

    node_modules/firebaseui/dist/esm.js:4883:8:
      4883 │         case 192:
           ╵         ~~~~
⠦ Building...
● [DEBUG] This call to "require" will not be bundled because the argument is not a string literal [unsupported-require-call]

    node_modules/express/lib/view.js:72:13:
      72 │     var fn = require(mod).__express;
         ╵              ~~~~~~~

● [DEBUG] This case clause will never be evaluated because it duplicates an earlier case clause [duplicate-case]

    node_modules/firebaseui/dist/esm.js:4861:8:
      4861 │         case 224:
           ╵         ~~~~

  The earlier case clause is here:

    node_modules/firebaseui/dist/esm.js:4847:8:
      4847 │         case 224:
           ╵         ~~~~

● [DEBUG] This case clause will never be evaluated because it duplicates an earlier case clause [duplicate-case]

    node_modules/firebaseui/dist/esm.js:4890:8:
      4890 │         case 192:
           ╵         ~~~~

  The earlier case clause is here:

    node_modules/firebaseui/dist/esm.js:4883:8:
      4883 │         case 192:
           ╵         ~~~~

● [DEBUG] Using direct eval with a bundler is not recommended and may cause problems [direct-eval]

    node_modules/lottie-web/build/player/lottie.js:14327:32:
      14327 │       var expression_function = eval('[function _expression_function(){' + val + ';scoped_bm_rt=$bm_rt}]')[0]; // eslint-disable-line no-eval
            ╵                                 ~~~~

  You can read more about direct eval and bundling here: https://esbuild.github.io/link/direct-eval

● [DEBUG] Using direct eval with a bundler is not recommended and may cause problems [direct-eval]

    node_modules/lottie-web/build/player/lottie.js:14327:32:
      14327 │       var expression_function = eval('[function _expression_function(){' + val + ';scoped_bm_rt=$bm_rt}]')[0]; // eslint-disable-line no-eval
            ╵                                 ~~~~

  You can read more about direct eval and bundling here: https://esbuild.github.io/link/direct-eval
⠏ Building...

  dashboard.module-SKN3URED.js                 641.9kb
  chunk-TRDLCWMT.js                            457.9kb
  chunk-TCWFX2OP.js                            353.2kb
  lottie-2DXNGVHK.js                           300.8kb
  landing.module-WNLSJS2C.js                   248.1kb
  esm-JIBECP67.js                              241.0kb
  chunk-7TNZHTMF.js                            177.2kb
  chunk-XO5U7OM6.js                            115.8kb
  chunk-CZVGQAUF.js                             98.8kb
  flickity-LRPAAVJJ.js                          49.5kb
  cropper.esm-SMYEZKPD.js                       37.2kb
  chunk-4WZ7BYRL.js                             31.6kb
  chunk-DTV5PRJY.js                             15.6kb
  waves.component-A6GXTZDP.js                   13.1kb
  ken-burns.component-Z76SXEAB.js                7.6kb
  chunk-VXWYNNZW.js                              4.3kb
  chunk-SUV4EREZ.js                              3.2kb
  ...and 10 more output files...

⠋ Building...

  server.mjs          827.2kb
  xhr2-HFH3W27K.mjs    11.9kb
  chunk-GFUZYSQG.mjs    1.2kb

⚡ Done in 5107ms
● [DEBUG] Using direct eval with a bundler is not recommended and may cause problems [direct-eval]

    node_modules/@protobufjs/inquire/index.js:13:14:
      13 │     var mod = eval("quire".replace(/^/, "re"))(moduleName); // eslint-disable-line no-eval
         ╵               ~~~~

  You can read more about direct eval and bundling here: https://esbuild.github.io/link/direct-eval


  chunk-HCT7J33W.mjs                            778.3kb
  dashboard.module-EQ2BXEUI.mjs                 642.0kb
  chunk-TCHICX4X.mjs                            468.1kb
  main.server.mjs                               435.4kb
  chunk-NGKSIHBQ.mjs                            352.9kb
  lottie-L2XGBWI3.mjs                           300.8kb
  esm-4KAGCK6Y.mjs                              250.5kb
  landing.module-MIWFZB35.mjs                   248.2kb
  chunk-IULWPRNK.mjs                            202.5kb
  chunk-5O64WG6G.mjs                             98.9kb
  flickity-YU4KQ552.mjs                          49.6kb
  cropper.esm-JAVITYCY.mjs                       37.2kb
  chunk-AFQASQ3R.mjs                             31.6kb
  chunk-WUY6AJ2G.mjs                             15.7kb
  waves.component-WXKAN4UX.mjs                   13.2kb
  xhr2-IMDMNIVD.mjs                              11.8kb
  ken-burns.component-OOVH4RP7.mjs                7.6kb
  ...and 11 more output files...

⠋ Building...

And it stays in this last step here forever...

Your Environment

Angular CLI: 19.0.2
Node: 22.2.0
Package Manager: npm 10.9.1
OS: darwin arm64

Angular: 19.0.1
... animations, common, compiler, compiler-cli, core, forms
... localize, platform-browser, platform-browser-dynamic
... platform-server, router

Package                      Version
------------------------------------------------------
@angular-devkit/architect    0.1900.2
@angular-devkit/core         18.2.12
@angular-devkit/schematics   18.2.12
@angular/build               19.0.2
@angular/cdk                 19.0.0
@angular/cli                 19.0.2
@angular/material            19.0.0
@angular/ssr                 19.0.2
@schematics/angular          19.0.2
rxjs                         7.8.1
typescript                   5.6.3

Anything else relevant?

No response

[alan-agius4]

What is likely happening here is that the application is unable to reach a stable state. This instability can be caused by various factors, including the use of timeouts and intervals.

Unfortunately, without a reproducible, identifying the root cause is not possible.

[javiermarinros]

That was my first thought too: the app’s stability. However, it’s working fine with the dev server, even serving some of the routes as prerendered.

Is there a way to identify which route is being built or causing the stability issue? It doesn’t seem like good UX to just show a Building... message indefinitely. Should the builder include a timeout and warn the user if it gets stuck somewhere?

[alan-agius4]

I have a PR to add a timeout #28983

[javiermarinros]

I've been running some additional tests, and the same issue occurs with a newly created project using ng new, and opting in to the new Server Routing and App Engine APIs 😕

[alan-agius4]

Can you try to update your Node.js version to 22.11? I do recall earlier versions of Node.js 22 had a regressions for ESM loader hooks.

[javiermarinros]

That was it! Using node 22.11 everything is working 😄

Thank you Alan!

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