Angular项目执行ng serve报错：找不到@angular-devkit/build-angular模块

Let's break down how to fix this issue based on your setup and the error details:

Key Observation from Your Error #

Notice that the error references C:\Users\Brandon\project-name\node_modules instead of C:\Users\Brandon\project-name\frontend\node_modules. This suggests your project might be looking for dependencies in the parent directory rather than its own node_modules folder—this is likely the root cause.

Step-by-Step Solutions #

1. Fix Dependency Installation Path #

First, check if there's a node_modules folder inside your frontend directory. If it's missing (and instead exists in the parent project-name folder), you probably ran npm install from the wrong directory.

Fix this by navigating directly to your project folder and running a clean install:

cd C:\Users\Brandon\project-name\frontend
npm ci

Using npm ci ensures a strict, clean install that matches exactly the versions in your package-lock.json, avoiding any accidental version mismatches.

2. Ensure npm Version Compatibility for Angular 6 #

Angular 6 works best with npm 6.x. If you're using a newer npm version (like 7+), it can introduce compatibility issues with older Angular packages.

• Check your current npm version:

  npm -v
  

• If you're on npm 7 or higher, downgrade to npm 6:

  npm install -g npm@6
  

Then re-run npm ci in your frontend folder.

3. Align Global and Local Angular CLI Versions #

Mismatched global and local CLI versions can cause unexpected errors. Your project uses @angular/cli@6.0.3, so make sure your global CLI matches this version:

• Uninstall the global Angular CLI:

  npm uninstall -g @angular/cli
  

• Install the exact version matching your project:

  npm install -g @angular/cli@6.0.3
  

• Reinstall local dependencies in your frontend folder:

  npm ci
  

4. Full Cleanup and Reinstall #

If the above steps don't work, perform a thorough reset:

• Delete the node_modules folder and lock files in your frontend directory:

  # On Windows Command Prompt
  rmdir /s /q node_modules
  del package-lock.json
  
  # On PowerShell
  Remove-Item -Recurse -Force node_modules
  Remove-Item package-lock.json
  

• Clear the npm cache:

  npm cache clean --force
  

• Reinstall dependencies:

  npm ci
  

5. Verify Configuration Files #

Your package.json and angular.json are correctly configured for Angular 6—they reference the compatible version of @angular-devkit/build-angular and the right builders for serving/building the project. No changes are needed here unless the above steps don't resolve the issue.

After completing these steps, try running ng serve --open again—it should launch your Angular app successfully.

内容的提问来源于stack exchange，提问作者Brandon Lumsden