Warning while building library

🐞 Bug report

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Description

When we create a library named my-lib, angular cli adds the following to tsconfig.json:

  "my-lib": [
    "dist/my-lib/my-lib",
    "dist/my-lib"
  ]

When we build the library using ng build my-lib, we see the following warning several times in the console:

Warning: The basePath "/somepath/my-workspace/dist/my-lib/my-lib.d.ts" computed from baseUrl "/somepath/my-workspace" and path mapping "/somepath/my-workspace/dist/my-lib/my-lib.d.ts" does not exist in the file-system.
It will not be scanned for entry-points.

In the end, the build succeeds, but the warning is annoying. It was printed 9 time while building.

🔬 Minimal Reproduction

ng new my-workspace --create-application=false
cd my-workspace
ng generate library my-lib
ng build my-lib

🌍 Your Environment

Angular CLI: 9.1.0
Node: 13.12.0
OS: linux x64

Angular: 9.1.1
... animations, common, compiler, compiler-cli, core, forms
... language-service, platform-browser, platform-browser-dynamic
... router
Ivy Workspace: Yes

Package                            Version
------------------------------------------------------------
@angular-devkit/architect          0.901.0
@angular-devkit/build-angular      0.901.0
@angular-devkit/build-ng-packagr   0.901.0
@angular-devkit/build-optimizer    0.901.0
@angular-devkit/build-webpack      0.901.0
@angular-devkit/core               9.1.0
@angular-devkit/schematics         9.1.0
@angular/cli                       9.1.0
@ngtools/webpack                   9.1.0
@schematics/angular                9.1.0
@schematics/update                 0.901.0
ng-packagr                         9.1.0
rxjs                               6.5.5
typescript                         3.8.3
webpack                            4.42.0

[alan-agius4]

@Annie-Huang, this has been closed as it was fixed via https://github.com/angular/angular/pull/36525

The fix will be available in 9.1.2

Yes, the above warning can be ignored.

[Roaders]

What confuses me is that I still get the warning when I move the paths from the base tsconfig to tsconfig.app.json. I don’t want the path mappings to be available to my library (I’ll just use relative paths), I only want it available to my app.

In fact. it still happens if I remove all paths from all tsconfig files???

Why do I still get the warnings?