Are you tired of seeing the “Vercel deploy success” message, only to be met with an error when accessing your web application? You’re not alone! In this article, we’ll dive deep into the mysterious issue of Nextjs 14 and Undici wrong version conflicts, and provide you with a step-by-step guide to resolve this frustrating problem once and for all.
What’s Causing the Error?
Before we dive into the solution, let’s take a closer look at what’s causing this error in the first place. The issue typically arises when there’s a version mismatch between Nextjs and Undici, a popular HTTP/1.1 and HTTP/2 client library. When you deploy your Nextjs 14 application to Vercel, the platform might pick up an older version of Undici, which can lead to compatibility issues and errors.
Nextjs 14 and Undici Version Conflicts
In Nextjs 14, Undici is used as a dependency to handle HTTP requests. However, when you deploy your application to Vercel, the platform might install an older version of Undici, say 4.12.0, instead of the recommended 5.x version. This version mismatch can lead to unexpected behavior and errors, making it difficult to access your web application.
Resolving the Issue: A Step-by-Step Guide
Now that we’ve identified the root cause of the problem, let’s move on to the solution. Follow these steps to resolve the Nextjs 14 and Undici wrong version conflict:
Step 1: Check Your `package.json` File
First, open your `package.json` file and check the version of Undici specified in the dependencies section. Make sure it’s set to the latest version, which is 5.x at the time of writing. If it’s not, update the version to the latest one.
"dependencies": {
"undici": "^5.0.0",
// Other dependencies
}
Step 2: Update Your `next.config.js` File
In your `next.config.js` file, add the following configuration to ensure that Vercel uses the correct version of Undici:
module.exports = {
// Other configurations
experimental: {
undici: true,
},
}
This configuration tells Nextjs to use the Undici version specified in your `package.json` file.
Step 3: Create a `vercel.json` File
Create a new file called `vercel.json` in the root of your project, and add the following configuration:
{
"version": 2,
"builds": [
{
"src": "next.config.js",
"use": "@vercel/node-configuration",
"config": {}
}
]
}
This configuration tells Vercel to use the `next.config.js` file for building your application.
Step 4: Update Your `next` Script
In your `package.json` file, update the `next` script to include the `–experimental-undici` flag:
"scripts": {
"next": "next build --experimental-undici",
// Other scripts
}
This flag enables the experimental Undici feature in Nextjs, ensuring that the correct version is used.
Step 5: Redeploy Your Application
Finally, redeploy your application to Vercel using the following command:
vercel deploy
This should redeploy your application with the correct version of Undici, resolving the access web error issue.
Troubleshooting Common Issues
If you encounter any issues during the deployment process, refer to the following troubleshooting guide:
| Error Message | Solution |
|---|---|
| Error: Undici version mismatch | Check your `package.json` file and ensure that the Undici version is set to the latest 5.x version. |
| Error: Experimental Undici feature not enabled | Update your `next` script to include the `–experimental-undici` flag. |
| Error: Vercel deployment failed | Check your `vercel.json` file and ensure that it’s configured correctly. Try redeploying your application with the `–debug` flag to get more detailed error messages. |
Conclusion
In this article, we’ve explored the mysterious issue of Nextjs 14 and Undici wrong version conflicts, and provided a step-by-step guide to resolve the problem. By following these instructions and troubleshooting common issues, you should be able to deploy your Nextjs 14 application to Vercel successfully and access your web application without any errors. Remember to stay calm, be patient, and don’t hesitate to reach out to the Vercel and Nextjs communities for further assistance if needed.
Additional Resources
For further reading and exploration, check out the following resources:
- Nextjs Documentation: next.config.js
- Vercel Documentation: Configuration
- Undici Documentation: Getting Started
By following this guide and staying up-to-date with the latest developments in Nextjs and Vercel, you’ll be well-equipped to tackle any deployment issues that come your way. Happy coding!
Frequently Asked Questions
Having trouble accessing your Nextjs 14 app on Vercel despite a successful deployment? You’re not alone! We’ve got the answers to get you back on track.
Why does my Nextjs 14 app deploy successfully on Vercel but throw an error when I try to access it?
This might be due to a version conflict with undici, a dependency used by Nextjs. Vercel might be using an incompatible version of undici, causing the error. Try specifying the correct version of undici in your `package.json` file or updating your `next.config.js` to resolve the issue.
How do I check the version of undici being used by Vercel?
You can check the version of undici by running `vercel env` or `vercel build` with the `–debug` flag. This will display the environment variables and dependencies used by Vercel, including the version of undici. Alternatively, you can check your `package.json` file to see if undici is listed as a dependency with a specific version.
What if I’m using a monorepo with multiple packages? How do I ensure the correct version of undici is used?
In a monorepo setup, you can specify the version of undici in the `package.json` file of the root project or in the `package.json` file of the specific package that requires it. You can also use a ` resolutions` field in your `package.json` file to pin the version of undici across all packages.
I’ve updated my `package.json` file and `next.config.js` but I’m still getting errors. What’s next?
If you’ve updated your configuration files but still encounter issues, try redeploying your app to Vercel or running `vercel build` with the `–force` flag to rebuild your app. You can also check the Vercel documentation and Nextjs documentation for further troubleshooting steps or seek help from the community forums.
Is there a way to avoid this issue altogether in future deployments?
Yes! To avoid version conflicts with undici or other dependencies in the future, make sure to regularly update your dependencies and keep your `package.json` file up-to-date. You can also use a `lockfile` such as `yarn.lock` or `pnpm-lock.yaml` to ensure consistent dependency versions across environments.
