fix(@angular-devkit/build-angular): browser builder should not swollow error messages

Closes #14813

Author: alan-agius4

packages/angular/cli/models/architect-command.ts

@@ -270,10 +270,14 @@ export abstract class ArchitectCommand<
         },
       );
 
-      const result = await run.output.toPromise();
+      const { error, success } = await run.output.toPromise();
       await run.stop();
 
-      return result.success ? 0 : 1;
+      if (error) {
+        this.logger.error(error);
+      }
+
+      return success ? 0 : 1;
     }
   }
 

packages/angular_devkit/build_angular/src/angular-cli-files/utilities/service-worker/index.ts

@@ -102,7 +102,7 @@ export async function augmentAppWithServiceWorker(
   if (!configExists) {
     throw new Error(tags.oneLine`
       Error: Expected to find an ngsw-config.json configuration
-      file in the ${appRoot} folder. Either provide one or disable Service Worker
+      file in the ${getSystemPath(appRoot)} folder. Either provide one or disable Service Worker
       in your angular.json configuration file.
     `);
   }

packages/angular_devkit/build_angular/src/browser/index.ts

@@ -237,7 +237,7 @@ export function buildWebpackBrowser(
             })
             .pipe(
               map(() => ({ success: true })),
-              catchError(() => of({ success: false })),
+              catchError(error => of({ success: false, error: mapErrorToMessage(error) })),
             );
           } else {
             return of({ success });
@@ -252,7 +252,10 @@ export function buildWebpackBrowser(
               resolve(root, normalize(options.outputPath)),
               options.baseHref || '/',
               options.ngswConfigPath,
-            ).then(() => ({ success: true }), () => ({ success: false })));
+            ).then(
+              () => ({ success: true }),
+              error => ({ success: false, error: mapErrorToMessage(error) }),
+            ));
           } else {
             return of(buildEvent);
           }
@@ -267,4 +270,16 @@ export function buildWebpackBrowser(
   );
 }
 
+function mapErrorToMessage(error: unknown): string | undefined {
+  if (error instanceof Error) {
+    return error.message;
+  }
+
+  if (typeof error === 'string') {
+    return error;
+  }
+
+  return undefined;
+}
+
 export default createBuilder<json.JsonObject & BrowserBuilderSchema>(buildWebpackBrowser);