{"record":{"id":"c9369c36a407790b","repo":"angular/angular-cli","slug":"the-angular-devkit-build-angular-ng-packagr-bui","errorCode":null,"errorMessage":"The \"@angular-devkit/build-angular:ng-packagr\" builder is deprecated as part of Angular's Webpack support deprecation. Use \"@angular/build:ng-packagr\" instead. For more information, see https://angular.dev/tools/cli/build-system-migration.","messagePattern":"The \"@angular-devkit/build-angular:ng-packagr\" builder is deprecated as part of Angular's Webpack support deprecation\\. Use \"@angular/build:ng-packagr\" instead\\. For more information, see https://angular\\.dev/tools/cli/build-system-migration\\.","errorType":"console","errorClass":null,"httpStatus":null,"severity":"warning","filePath":"packages/angular_devkit/build_angular/src/builders/ng-packagr/index.ts","lineNumber":25,"sourceCode":" */\n\nimport { purgeStaleBuildCache } from '@angular/build/private';\nimport { BuilderContext, BuilderOutput, createBuilder } from '@angular-devkit/architect';\nimport type { NgPackagrOptions } from 'ng-packagr';\nimport { createRequire } from 'node:module';\nimport { join, resolve } from 'node:path';\nimport { Observable, catchError, from, map, of, switchMap } from 'rxjs';\nimport { normalizeCacheOptions } from '../../utils/normalize-cache';\nimport { Schema as NgPackagrBuilderOptions } from './schema';\n\n/**\n * @experimental Direct usage of this function is considered experimental.\n */\nexport function execute(\n  options: NgPackagrBuilderOptions,\n  context: BuilderContext,\n): Observable<BuilderOutput> {\n  context.logger.warn(\n    'The \"@angular-devkit/build-angular:ng-packagr\" builder is deprecated as part of Angular\\'s Webpack support deprecation. ' +\n      'Use \"@angular/build:ng-packagr\" instead. For more information, see https://angular.dev/tools/cli/build-system-migration.',\n  );\n\n  return from(\n    (async () => {\n      // Purge old build disk cache.\n      await purgeStaleBuildCache(context);\n\n      const root = context.workspaceRoot;\n      const workspaceRequire = createRequire(root + '/');\n      const ngPackagePath = workspaceRequire.resolve('ng-packagr');\n      const packager = (await import(ngPackagePath)).ngPackagr();\n\n      packager.forProject(resolve(root, options.project));\n\n      if (options.tsConfig) {\n        packager.withTsConfig(resolve(root, options.tsConfig));","sourceCodeStart":7,"sourceCodeEnd":43,"githubUrl":"https://github.com/angular/angular-cli/blob/bb72145f9ab45aee29f523236b3a25cd0813a841/packages/angular_devkit/build_angular/src/builders/ng-packagr/index.ts#L7-L43","documentation":"The @angular-devkit/build-angular:ng-packagr builder emits a deprecation warning as part of Angular's Webpack support deprecation, pointing users to the esbuild-based @angular/build:ng-packagr builder.","triggerScenarios":"Running `ng build` (or `ng packagr`) against a library project configured with the @angular-devkit/build-angular:ng-packagr builder on a recent Angular version.","commonSituations":"Library workspaces not yet migrated after `ng update`; build logs show repeated deprecation warnings.","solutions":["Switch the library build target's builder to @angular/build:ng-packagr in angular.json.","Run `ng update` to apply the builder migration automatically.","Suppress/ignore the warning until migration; the builder still works."],"exampleFix":"// angular.json library architect/build target\n// before\n\"builder\": \"@angular-devkit/build-angular:ng-packagr\"\n// after\n\"builder\": \"@angular/build:ng-packagr\"","handlingStrategy":"fallback","validationCode":"const cfg = require('./angular.json');\nconst usesDeprecated = JSON.stringify(cfg).includes('@angular-devkit/build-angular:ng-packagr');\nif (usesDeprecated) console.warn('Migrate library builds to @angular/build:ng-packagr');","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Migrate library targets to @angular/build:ng-packagr during upgrades.","Run `ng update` rather than hand-merging angular.json.","Add a CI check that fails on deprecated builder names."],"tags":["deprecation","angular","webpack","ng-packagr"],"backgroundTag":"webpack-builder-deprecated","analyzedSha":"bb72145f9ab45aee29f523236b3a25cd0813a841","analyzedAt":"2026-08-30T02:47:34.745Z","schemaVersion":2},"datasetVersion":"2026-08-30T03:17:51.788Z"}