Describe the bug

While initializing a new Next.js project with shadcn-ui using npx shadcn@latest init, the installation fails when attempting to install dependencies. The error occurs because @radix-ui/react-icons has a peer dependency requirement for "react@^16.x || ^17.x || ^18.x", but the project is using React 19.0.0-rc-69d4b800-20241021.

Error message:
npm error ERESOLVE unable to resolve dependency tree
npm error Found: react@19.0.0-rc-69d4b800-20241021
npm error Could not resolve dependency:
npm error peer react@"^16.x || ^17.x || ^18.x" from @radix-ui/react-icons@1.3.0

Current environment:

• Next.js 15
• React 19.0.0-rc-69d4b800-20241021
• npm (latest version)
• shadcn-ui (latest version)

The installation works fine with React 18, suggesting that @radix-ui/react-icons needs to be updated to support React 19 release candidates.

Potential solutions:

1. Update @radix-ui/react-icons peer dependencies to include React 19
2. Add a note in the documentation about React 19 compatibility
3. Add a version check in the CLI to warn users about React 19 compatibility issues

Affected component/components

shadcn-ui installation fails

How to reproduce

Steps to reproduce:

1. Create a new Next.js project with experimental features:
   ```bash
   npx create-next-app@latest my-app --typescript --tailwind --app

2. During the setup, select 'yes' for App Router and other default options

3. Navigate to the project directory:
   bash
   cd my-app

4. Try to initialize shadcn-ui:
   bash
   npx shadcn@latest init

5. Select configuration options:

   • Style: New York
   • Base color: Neutral
   • CSS variables: Yes

6. The installation will fail during the dependency installation step with the following error:

   npm error ERESOLVE unable to resolve dependency tree
   npm error Found: react@19.0.0-rc-69d4b800-20241021
   npm error Could not resolve dependency:
   npm error peer react@"^16.x || ^17.x || ^18.x" from @radix-ui/react-icons@1.3.0

You can verify the React version in your package.json:
{
"dependencies": {
"react": "19.0.0-rc-69d4b800-20241021",
"react-dom": "19.0.0-rc-69d4b800-20241021"
}
}

Codesandbox/StackBlitz link

No response

Logs

No response

System Info

System Information:

Operating System:
- Windows 8
- Working in Command Prompt

Node Environment:
- Node.js version: v20.17.0
- npm version: v10.9.0

Project Dependencies:
- Next.js: 15
- React: 19.0.0-rc-69d4b800-20241021
- React DOM: 19.0.0-rc-69d4b800-20241021
- Typescript: ^5
- Tailwind CSS: ^3.4.1

CLI Versions:
- create-next-app: latest
- shadcn-ui CLI: latest (@shadcn/ui)

Additional Context:
- Fresh installation with default configurations
- Using App Router
- Project created with TypeScript and Tailwind CSS enabled

Before submitting

• I've made research efforts and searched the documentation
• I've searched for existing issues