'ng serve' and 'ng build' hang with 100% CPU when updating Angular v19 to v20 to docker

[Trystan-SA]

Which @angular/* package(s) are the source of the bug?

compiler

Is this a regression?

Yes

Description

I tried to update my angular application from v19.x to v20.3. I'm angular using docker as a dev server. Since updating my angular packages. The 'ng serve' and 'ng build' tasks hang indefenitly and the server never start when spawing it from a docker container. Everything work well if I start it directly on my host.

List of updated packages :

 "@angular-devkit/architect": "0.1901.4", --> "^0.2003.2"
    "@angular-devkit/build-angular": "19.1.4", --> "^20.3.2"
    "@angular-devkit/core": "19.1.4", --> "^20.3.2"
    "@angular-devkit/schematics": "19.1.4", --> "^20.3.2"
    "@angular/animations": "19.2.14", --> "^20.3.1"
    "@angular/build": "^19.2.14", --> "^20.3.2"
    "@angular/cdk": "19.2.14", --> "^20.2.4"
    "@angular/cli": "~19.0.0", --> ""^20.3.2"
    "@angular/common": "19.2.14", --> "^20.3.1"
    "@angular/compiler": "19.2.14", --> "^20.3.1"
    "@angular/compiler-cli": "19.2.14", --> "^20.3.1"
    "@angular/core": "19.2.14", --> "^20.3.1"
    "@angular/forms": "19.2.14", --> "^20.3.1"
    "@angular/language-service": "19.2.14", --> "^20.3.1"
    "@angular/platform-browser": "19.2.14", --> "^20.3.1"
    "@angular/platform-browser-dynamic": "19.2.14", --> "^20.3.1"
    "@angular/router": "19.2.14", --> "^20.3.1"
    "@angular/service-worker": "^19.2.14", --> "^20.3.1"
    "@sentry/angular": "8.51.0", --> "10.13.0",
    "zone.js": "0.15.0" --> "0.15.1",
    "@analogjs/vite-plugin-angular": "^1.17.1", --> "^1.21.1"
    "@analogjs/vitest-angular": "^1.17.1", --> "^1.21.1"
    "@angular-eslint/eslint-plugin": "19.0.2", --> "20.3.0"
    "@angular-eslint/eslint-plugin-template": "19.0.2", --> "20.3.0"
    "@angular-eslint/template-parser": "19.0.2", --> "20.3.0",
    "@schematics/angular": "19.1.4", -->  "20.3.2",
    "ng-mocks": "14.13.2", --> "14.13.5"
    "ng-packagr": "19.1.0", --> "20.3.0",
    "typescript": "5.6.3", --> "5.9.2"

I tried multiples commands like '--verbose' to get some info about where the ng command hang. But nothing get printed. I'm completly clueless.

I'm running my docker app like this : ng build --verbose --configuration production or ng serve --port 4200 --poll 2000 --host 0.0.0.0 --disable-host-check --live-reload --proxy-config path/to/proxy/config.json

I observe 100% CPU utilization on my docker container (1 core). But it still do nothing after 10 minutes. The dev server on my host (16 core) start in 30 seconds. Any clues how to debug it ?

Thanks a lot !

Please provide a link to a minimal reproduction of the bug

No response

Please provide the exception or error you saw

Please provide the environment you discovered this bug in (run ng version)

Angular CLI: 20.3.2
Node: 22.15.0
Package Manager: npm 10.9.2
OS: linux x64
    

Angular: 20.3.1
... animations, common, compiler, compiler-cli, core, forms
... language-service, platform-browser, platform-browser-dynamic
... router, service-worker

Package                         Version
---------------------------------------
@angular-devkit/architect       0.2003.2
@angular-devkit/build-angular   20.3.2
@angular-devkit/core            20.3.2
@angular-devkit/schematics      20.3.2
@angular/build                  20.3.2
@angular/cdk                    20.2.4
@angular/cli                    20.3.2
@schematics/angular             20.3.2
ng-packagr                      20.3.0
rxjs                            7.8.0
typescript                      5.9.2
webpack                         5.101.3
zone.js                         0.15.1

Anything else?

No response

[clydin]

Can you reproduce the issue with a newly generated v20 project?

[Trystan-SA]

I updated my angular.json file based on the one generated when creating a new project in angular V20.

The previous angular.json used @angular-devkit/build-angular:browser which have been moved to @angular repo I think.
I updated it with @angular/build:application and the build step work fine now.