Context

I created several independent angular libraries in different folders:

• /home/user/lib1
• /home/user/lib2
• /home/user/lib3

The lib2 and lib3 libraries have a dependency on the lib1 library.

// Example of the lib3.module.ts 
import {Lib1Module} from '@libs/lib1';

@NgModule({
  declarations: [Lib3Component],
  imports: [
    Lib1Module
  ],
  exports: [Lib3Component]
})
export class Lib3Module { }

However, when I create a symlink of lib1 and import it into lib2 and lib3 with the command "npm link lib1", I get a build issue (bellow, you can see the error message).

ERROR: : Unexpected value 'Lib1Module in /home/user/Documents/multiple-angular-lib/lib1/dist/libs/lib1/libs-lib1.d.ts' imported by the module 'Lib2Module in /home/user/Documents/multiple-angular-lib/lib2/projects/libs/lib2/src/lib/lib2.module.ts'. Please add a @NgModule annotation.

The most amazing thing in all this, is, if I deploy my component on the official repository of npm, it will work. It's the same structure and files! So there is a problem with the symlink.

What I tried

I tried to follow the solutions proposed here:

• https://github.com/angular/angular-cli/issues/10665

How to reproduce my problem

I've reproduced an example here: https://github.com/fjoalland/multiple-angular-lib/tree/master

Just follow the steps and you should have the same error as me.

Error message

Bellow, the full error I got when I try to build the lib2 with a symlink of the lib1

[root@user lib2]# ng build
Building Angular Package

------------------------------------------------------------------------------
Building entry point '@libs/lib2'
------------------------------------------------------------------------------
Compiling TypeScript sources through ngc
ERROR: : Unexpected value 'Lib1Module in /home/user/Documents/multiple-angular-lib/lib1/dist/libs/lib1/libs-lib1.d.ts' imported by the module 'Lib2Module in /home/user/Documents/multiple-angular-lib/lib2/projects/libs/lib2/src/lib/lib2.module.ts'. Please add a @NgModule annotation.

An unhandled exception occurred: : Unexpected value 'Lib1Module in /home/user/Documents/multiple-angular-lib/lib1/dist/libs/lib1/libs-lib1.d.ts' imported by the module 'Lib2Module in /home/user/Documents/multiple-angular-lib/lib2/projects/libs/lib2/src/lib/lib2.module.ts'. Please add a @NgModule annotation.

See "/tmp/ng-V1D4qF/angular-errors.log" for further details.

The contents of the angular-error.log file:

[error] Error: : Unexpected value 'Lib1Module in D:/Documents/multiple-angular-lib/lib1/dist/libs/lib1/libs-lib1.d.ts' imported by the module 'Lib2Module in D:/Documents/multiple-angular-lib/lib2/projects/libs/lib2/src/lib/lib2.module.ts'. Please add a @NgModule annotation.

    at Object.<anonymous> (D:\Documents\multiple-angular-lib\lib2\node_modules\ng-packagr\lib\ngc\compile-source-files.js:73:19)
    at Generator.next (<anonymous>)
    at fulfilled (D:\Documents\multiple-angular-lib\lib2\node_modules\ng-packagr\lib\ngc\compile-source-files.js:4:58)