ng serve with @angular/build: DevTools file search not working

Reproduce the issue with a new Angular app using ng serve and @angular/build, then compare it with Angular 19 using @angular-devkit/build-angular. Check how the serve output is exposed in Chrome or Edge DevTools Sources. Done means cross-file search returns content in Angular 20+ as it does in Angular 19, with the relevant regression covered by the project's tests.

Command

serve

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

angular19 with @angular-devkit/build-angular

Description

When I try to migrate an Angular 20 project from @angular-devkit/build-angular to the new @angular/build, I notice that when running ng serve and opening the browser DevTools → Sources, searching for content across all files does not return any results.

Minimal Reproduction

Angular versions: 20, 21, and 22 (out of the box)
Browser: Edge and Chrome
Operating System: Windows and Linux
SSR: off
Zoneless: off

Steps:

1. Create a new Angular app with ng new v20.
2. Run ng serve.
3. Open the browser and go to DevTools → Sources.
4. Try to search for content across all files.

Steps:

1. Create a new Angular app with ng new v22.
2. Run ng serve.
3. Open the browser and go to DevTools → Sources.
4. Try to search for content across all files.

Exception or Error

Your Environment

Angular CLI: 20.3.31
Node: 22.14.0
Package Manager: npm 10.9.2
OS: linux x64
    

Angular: 20.3.25
... common, compiler, compiler-cli, core, forms
... platform-browser, router

Package                      Version
------------------------------------
@angular-devkit/architect    0.2003.31
@angular-devkit/core         20.3.31
@angular-devkit/schematics   20.3.31
@angular/build               20.3.31
@angular/cli                 20.3.31
@schematics/angular          20.3.31
rxjs                         7.8.2
typescript                   5.9.3
zone.js                      0.15.1

---------------------------------------

Angular CLI       : 22.0.5
Angular           : 22.0.5
Node.js           : 24.18.0
Package Manager   : npm 11.16.0
Operating System  : linux x64

┌───────────────────────────┬───────────────────┬───────────────────┐
│ Package                   │ Installed Version │ Requested Version │
├───────────────────────────┼───────────────────┼───────────────────┤
│ @angular/build            │ 22.0.5            │ ^22.0.5           │
│ @angular/cli              │ 22.0.5            │ ^22.0.5           │
│ @angular/common           │ 22.0.5            │ ^22.0.0           │
│ @angular/compiler         │ 22.0.5            │ ^22.0.0           │
│ @angular/compiler-cli     │ 22.0.5            │ ^22.0.0           │
│ @angular/core             │ 22.0.5            │ ^22.0.0           │
│ @angular/forms            │ 22.0.5            │ ^22.0.0           │
│ @angular/platform-browser │ 22.0.5            │ ^22.0.0           │
│ @angular/router           │ 22.0.5            │ ^22.0.0           │
│ rxjs                      │ 7.8.2             │ ~7.8.0            │
│ typescript                │ 6.0.3             │ ~6.0.2            │
│ vitest                    │ 4.1.9             │ ^4.0.8            │
└───────────────────────────┴───────────────────┴───────────────────┘

Anything else relevant?

Angula version: 19 (out of the box)
Browser: Edge and Chrome
Operating System: Windows and Linux
SSR: off

Steps:

1. Create a new Angular app with ng new v19.
2. Run ng serve.
3. Open the browser and go to DevTools → Sources.
4. Try to search for content across all files.

Result:
The search works correctly in Angular 19.

Angular CLI: 19.2.27
Node: 22.14.0
Package Manager: npm 10.9.2
OS: linux x64

Angular: 19.2.25
... common, compiler, compiler-cli, core, forms
... platform-browser, platform-browser-dynamic, router

Package Version

@angular-devkit/architect 0.1902.27
@angular-devkit/build-angular 19.2.27
@angular-devkit/core 19.2.27
@angular-devkit/schematics 19.2.27
@angular/cli 19.2.27
@schematics/angular 19.2.27
rxjs 7.8.2
typescript 5.7.3
zone.js 0.15.1