title: How to fix ng build <lib> error when renaming public_api.ts to public-api.ts in angular8 upgrade
body: <p>I am in the middle of migrating angular 7 to angular 8 for my company's component library that was built with 'ng generate library '. I tried to be as close to standard angular cli build as possible. I created a brand new app and a library with "@angular/cli": "~8.2.0". </p>
  
  <p><a href="https://github.com/Annie-Huang/my-angular8-app/tree/create-lib" rel="noreferrer">https://github.com/Annie-Huang/my-angular8-app/tree/create-lib</a></p>
  
  <p>I noticed in angular 8, they change public_api.ts to public-api.ts
  <a href="https://github.com/Annie-Huang/my-angular8-app/blob/create-lib/projects/ea-ui/src/public-api.ts" rel="noreferrer">https://github.com/Annie-Huang/my-angular8-app/blob/create-lib/projects/ea-ui/src/public-api.ts</a></p>
  
  <p>So I renamed the entry file from the existing library from public_api.ts to public-api.ts
  And also update it in ng-package.json</p>
  
  <p>And I get this error of </p>
  
  <pre><code>Bradleys-MacBook-Pro:ea-component-library anniehuang$ ng build ea-ui
  Building Angular Package
  ERROR: error TS6053: File '/Users/anniehuang/projects/ea-component-library/projects/ea-ui/src/public_api.ts' not found.
  
  An unhandled exception occurred: error TS6053: File '/Users/anniehuang/projects/ea-component-library/projects/ea-ui/src/public_api.ts' not found.
  
  See "/private/var/folders/sw/1rxh903n6y39kkwbgr737n8m0000gp/T/ng-SE3jbI/angular-errors.log" for further details.
  </code></pre>
  
  <p>When I built it in the brand new angular 8 app in my own repo (<code>ng build ea-ui</code>). I don't have this error.</p>
  
  <p>And there is no public_api.ts string when I did global search on the company component library.</p>
  
  <pre><code>ng-package.json:
  ---------------------
  {
    "$schema": "../../node_modules/ng-packagr/ng-package.schema.json",
    "dest": "../../dist/ea-ui",
    "lib": {
      "entryFile": "src/public-api.ts"
    }
  }
  
  public-api.ts (file content not change, just renamed):
  ----------------------------------------------------------
  export * from './lib/accordion/accordion.component';
  export * from './lib/accordion/accordion.module';
  export * from './lib/autocomplete/autocomplete-trigger.directive';
  export * from './lib/autocomplete/autocomplete.component';
  export * from './lib/autocomplete/autocomplete.module';
  ....
  </code></pre>
  
  <pre><code>Bradleys-MacBook-Pro:ea-component-library anniehuang$ ng build ea-ui
  Building Angular Package
  ERROR: error TS6053: File '/Users/anniehuang/projects/ea-component-library/projects/ea-ui/src/public_api.ts' not found.
  
  An unhandled exception occurred: error TS6053: File '/Users/anniehuang/projects/ea-component-library/projects/ea-ui/src/public_api.ts' not found.
  
  See "/private/var/folders/sw/1rxh903n6y39kkwbgr737n8m0000gp/T/ng-SE3jbI/angular-errors.log" for further details.
  
  Open up angular-errors.log:
  ------------------------------
  Bradleys-MacBook-Pro:~ anniehuang$ cat /private/var/folders/sw/1rxh903n6y39kkwbgr737n8m0000gp/T/ng-MET38P/angular-errors.log
  [error] Error: error TS6053: File '/Users/anniehuang/projects/ea-component-library/projects/ea-ui/src/public_api.ts' not found.
  
      at analyseEntryPoint (/Users/anniehuang/projects/ea-component-library/node_modules/ng-packagr/lib/ng-v5/init/analyse-sources.transform.js:45:15)
      at MapSubscriber.exports.analyseSourcesTransform.rxjs_1.pipe.operators_1.map.graph [as project] (/Users/anniehuang/projects/ea-component-library/node_modules/ng-packagr/lib/ng-v5/init/analyse-sources.transform.js:15:9)
      at MapSubscriber._next (/Users/anniehuang/projects/ea-component-library/node_modules/rxjs/internal/operators/map.js:49:35)
      at MapSubscriber.Subscriber.next (/Users/anniehuang/projects/ea-component-library/node_modules/rxjs/internal/Subscriber.js:66:18)
      at SwitchMapSubscriber.notifyNext (/Users/anniehuang/projects/ea-component-library/node_modules/rxjs/internal/operators/switchMap.js:86:26)
      at InnerSubscriber._next (/Users/anniehuang/projects/ea-component-library/node_modules/rxjs/internal/InnerSubscriber.js:28:21)
      at InnerSubscriber.Subscriber.next (/Users/anniehuang/projects/ea-component-library/node_modules/rxjs/internal/Subscriber.js:66:18)
      at MapSubscriber._next (/Users/anniehuang/projects/ea-component-library/node_modules/rxjs/internal/operators/map.js:55:26)
      at MapSubscriber.Subscriber.next (/Users/anniehuang/projects/ea-component-library/node_modules/rxjs/internal/Subscriber.js:66:18)
  
  </code></pre>