Running into a wall of red text in your terminal is a rite of passage for anyone setting up a project on a Raspberry Pi. If you were trying to build PopeBot (or any Next.js project) and got hit with an EACCES: permission denied error, don’t worry—you haven’t broken anything.
This guide will walk you through exactly why this happens and how to fix it so you can get your bot back online.
The Error: Understanding “EACCES”
When you see uncaughtException [Error: EACCES: permission denied, open '.../.next/trace'], your operating system is essentially saying: “I see you’re trying to write to this file, but you aren’t the person who created it, and I’m not letting you touch it.”
In the case of a Raspberry Pi, this usually happens because of The Sudo Trap. At some point, a command was run using sudo (SuperUser Do). This caused the system to create folders—like your .next build folder—under the “root” user’s ownership. Now, when you try to run a normal npm run build as your regular user (kafechew), you don’t have the “clearance” to modify those root-owned files.
How to Fix the Permission Mismatch
Follow these three steps to reclaim your project and finish the build.
1. Reclaim Ownership of Your Files
Instead of using sudo to force the build (which can cause even more headaches later), the best practice is to tell the system that you own these files.
Run this command from inside your keaibot directory:
sudo chown -R $USER:$USER /home/kafechew/keaibotWhat this does:
sudo: Gives you temporary admin power to change ownership.chown: Stands for “Change Owner.”-R: Stands for “Recursive.” it applies the change to every single file and sub-folder inside the directory.$USER:$USER: This automatically fills in your current username (e.g.,kafechew).
2. Clear the “Ghost” Build Files
Even after changing permissions, old build artifacts can sometimes cause conflicts. It’s safest to delete the existing build directory and let Next.js start from scratch.
rm -rf .nextNote: Be careful with rm -rf. Always double-check that you are in the correct folder before running it!
3. Run the Build Again
Now that your user owns the folder and the old, restricted files are gone, you can run the build command normally:
npm run buildPro-Tip
You should know that using sudo with npm is generally considered bad practice. When you use sudo npm install or sudo npm run build, you risk:
- Security Vulnerabilities: Giving third-party scripts from the internet root access to your entire Raspberry Pi.
- Permission Hell: Constantly having to fix the exact error we just solved.
The Golden Rule: If npm tells you that you need sudo to install something, it’s usually better to fix the permissions of your node_modules or use a version manager like NVM (Node Version Manager) rather than giving in to the sudo prompt.