[ng 9.1.0] entryPoints error for every components

Bug description:

Compiling @ng-bootstrap/ng-bootstrap : module as esm5
Error: Tried to write D:/test/student/node_modules/@ng-bootstrap/ng-bootstrap/accordion/accordion-config.d.ts.__ivy_ngcc_bak with an ngcc back up file but it already exists so not writing, nor backing up, D:/test/student/node_modules/@ng-bootstrap/ng-bootstrap/accordion/accordion-config.d.ts.
This error may be because two or more entry-points overlap and ngcc has been asked to process some files more than once.
You should check other entry-points in this package and set up a config to ignore any that you are not using.
Error: Tried to write D:/test/student/node_modules/@ng-bootstrap/ng-bootstrap/accordion/accordion.d.ts.__ivy_ngcc_bak with an ngcc back up file but it already exists so not writing, nor backing up, D:/test/student/node_modules/@ng-bootstrap/ng-bootstrap/accordion/accordion.d.ts.
This error may be because two or more entry-points overlap and ngcc has been asked to process some files more than once.
You should check other entry-points in this package and set up a config to ignore any that you are not using.
Error: Tried to write D:/test/student/node_modules/@ng-bootstrap/ng-bootstrap/accordion/accordion.module.d.ts.__ivy_ngcc_bak with an ngcc back up file but it already exists so not writing, nor backing up, D:/test/student/node_modules/@ng-bootstrap/ng-bootstrap/accordion/accordion.module.d.ts.
This error may be because two or more entry-points overlap and ngcc has been asked to process some files more than once.
You should check other entry-points in this package and set up a config to ignore any that you are not using.
Error: Tried to write D:/test/student/node_modules/@ng-bootstrap/ng-bootstrap/alert/alert-config.d.ts.__ivy_ngcc_bak with an ngcc back up file but it already exists so not writing, nor backing up, D:/test/student/node_modules/@ng-bootstrap/ng-bootstrap/alert/alert-config.d.ts.
This error may be because two or more entry-points overlap and ngcc has been asked to process some files more than once.
You should check other entry-points in this package and set up a config to ignore any that you are not using.
Error: Tried to write D:/test/student/node_modules/@ng-bootstrap/ng-bootstrap/alert/alert.d.ts.__ivy_ngcc_bak with an ngcc back up file but it already exists so not writing, nor backing up, D:/test/student/node_modules/@ng-bootstrap/ng-bootstrap/alert/alert.d.ts.

Link to minimally-working StackBlitz that reproduces the issue:

You can fork a StackBlitz from one of our demos and use it as a starting point.

Please note that we can not act on bug reports without a minimal reproduction scenario in a StackBlitz. Here is why: https://github.com/ng-bootstrap/ng-bootstrap#you-think-youve-found-a-bug

Versions of Angular, ng-bootstrap and Bootstrap:

Angular:

ng --version

     _                      _                 ____ _     ___
    / \   _ __   __ _ _   _| | __ _ _ __     / ___| |   |_ _|
   / △ \ | '_ \ / _` | | | | |/ _` | '__|   | |   | |    | |
  / ___ \| | | | (_| | |_| | | (_| | |      | |___| |___ | |
 /_/   \_\_| |_|\__, |\__,_|_|\__,_|_|       \____|_____|___|
                |___/


Angular CLI: 9.1.0
Node: 10.16.3
OS: win32 x64

Angular: 9.1.0
... animations, cli, 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-optimizer   0.901.0
@angular-devkit/build-webpack     0.901.0
@angular-devkit/core              9.1.0
@angular-devkit/schematics        9.1.0
@ngtools/webpack                  9.1.0
@schematics/angular               9.1.0
@schematics/update                0.901.0
rxjs                              6.5.4
typescript                        3.8.3
webpack                           4.42.0

ng-bootstrap: “@ng-bootstrap/ng-bootstrap”: “^6.0.2”,

Bootstrap: “bootstrap”: “^4.4.1”,

[indraraj26]

Thank you @maxokorokov

Problem: i stopped ng serve in middle of compiling then re-run ng serve. Now I have just deleted @ng-bootstrap and re-compile with es5 it is working fine.

Closing: As this is not an issue of @ng-bootstrap https://github.com/angular/angular/issues/36393

[maxokorokov]

Ok, clean install on Windows on my side works fine:

Angular CLI: 9.1.0
Node: 12.10.0
OS: win32 x64
Angular: 9.1.0

The only difference from your report is Compiling @ng-bootstrap/ng-bootstrap : es2015 as esm2015 by default. But again it also works if I change target to es5.

Another visible difference is node version, but it works fine with 10.16.3 on my side too.

I don’t think it’s the ng-bootstrap issue at this point, would need a reproduction scenario.