Angular/Cli AOT with custom library containing another node_modules folder

Question

I'm hitting an issue with AOT compilation and custom packages. In my scenario I have an Angular/Cli project which installs my own package (Package A). Package A has a dependency on Package B which contains a service.

NPM install of Package A results in a node_modules structure of:

• node_modules
  • package_a
    • (package_a files)
    • node_modules
      • package_b
        • (package_b files)
        • test.service.ts

This appears to make sense, as Package A is dependent on a certain version of Package B, therefore Package B is installed within a nested node_modules folder. Also I have ensured Package A exports TestService from Package B so it will be available.

The issue I have is when trying to access the Service in Package B from the main project:

app.component.ts

import { Component } from '@angular/core';
import { TestService } from 'package_a';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css'],
  providers: [TestService]
})

export class AppComponent {
  constructor(
    private log: TestService,
  ) {}

  ngOnInit(): void {

    // call function from package_b
  }
}

First off, when I run ng serve everything works perfectly, no issues at all. However, when I try to build the project using AOT compilation, it fails with an error: ERROR in ... Cannot find module.

If I install Package B separately, so there is an instances of it in the main node_modules directory, the whole thing works. Even if the nested version is different, it will use the nested version correctly as defined in Package A.

• node_modules
  • package_a
    • (package_a files)
    • node_modules
      • package_b [version 1.0.0]
        • (package_b files)
        • test.service.ts
  • package_b [version 2.0.0]
    • (package_b files)
    • test.service.ts

Any ideas how I can stop the need for the additional installation of Package B? Is there something I'm missing to point to the nested version before the main version?