Iam receiving const ngDevMode: boolean; this error while trying to use it with Angular 19

[Arunalexuiux]

node_modules/@ngneat/helipopper/config/tippy.types.d.ts:35:11 - error TS2451: Cannot redeclare block-scoped variable 'ngDevMode'.

35 const ngDevMode: boolean;

Once i comment the code in tippy.types.d.ts files its working as expected
declare global {
// const ngDevMode: boolean;
}

[Arunalexuiux]

it works locally after comment but while building since npm install runs at build time iam getting build error

[alexsukhodolsky]

This is causing build issues, preventing me from successfully integrating the library into my application :-( . Any chance the workaround can be merged in?

[antoprudenzano]

UP this, it is a real problem, using angular 20.

[KeithGillette]

I am encountering this issue as well, on tsc of a project after attempting to upgrade to version 11.1.3 in an Angular 20.1.3 project:

node_modules/@angular/core/event_dispatcher.d.d.ts(22,11): error TS2451: Cannot redeclare block-scoped variable 'ngDevMode'.
node_modules/@ngneat/helipopper/config/tippy.types.d.ts(35,11): error TS2451: Cannot redeclare block-scoped variable 'ngDevMode'.

[nawideck]

Hi,

I'm encountering the same TypeScript compilation error when building the project.
I'm using Angular 20.

✘ [ERROR] TS2451: Cannot redeclare block-scoped variable 'ngDevMode'. [plugin angular-compiler]

    node_modules/@ngneat/helipopper/config/tippy.types.d.ts:35:10:
      35 │     const ngDevMode: boolean;
         ╵           ~~~~~~~~~

  'ngDevMode' was also declared here.

    node_modules/@angular/core/event_dispatcher.d.d.ts:22:10:
      22 │     const ngDevMode: null | NgDevModePerfCounters;
         ╵           ~~~~~~~~~

[Polatrite]

Until the authors respond with a fix, a temporary workaround is to modify your tsconfig.json, adding compilerOptions.skipLibCheck: true:

{
    "compilerOptions": {
         ...
         "skipLibCheck": true,
         ...
    }
}

I don't recommend this as a long-term solution because lib checking is part of the safety that Typescript brings.

[Polatrite]

I created a PR to fix this issue: #188