🐞 Bug report

Command (mark with an x)

• new
• build
• serve
• test
• e2e
• generate
• add
• update
• lint
• xi18n
• run
• config
• help
• version
• doc

Is this a regression?

no

Description

If a compilation includes child compilations as is the case when using worker-loader for example (or many other webpack loaders/plugins) the build process can fail and exit without providing any info but the exit code being 1.

🔬 Minimal Reproduction

clone this, run ng build, no errors will be shown except of non-0 exit code or "failed to compile" in serve mode.
anything with a child compiler emits errors into it's own errors object.
you code in createBrowserLoggingCallback
which delegates to (stats.hasErrors() does not take into account the possibility of errors in child compilers.

🔥 Exception or Error

 the problem is the the error is not shown ;-) 

🌍 Your Environment

 Angular CLI: 8.3.23 Node: 12.16.2 OS: win32 x64 Angular: 8.2.14 ... animations, common, compiler, compiler-cli, core, elements ... forms, language-service, platform-browser ... platform-browser-dynamic, platform-server, router Package Version ------------------------------------------------------------ @angular-devkit/architect 0.803.23 @angular-devkit/build-angular 0.803.23 @angular-devkit/build-ng-packagr 0.803.26 @angular-devkit/build-optimizer 0.803.23 @angular-devkit/core 8.3.23 @angular-devkit/schematics 8.3.23 @angular/cdk 8.2.3 @angular/cli 8.3.23 @angular/flex-layout 8.0.0-beta.27 @schematics/angular 8.3.23 @schematics/update 0.803.23 ng-packagr 5.7.1 rxjs 6.5.5 typescript 3.5.3 webpack 4.29.6