Dev Container Features Not Installing Extensions

Bug Reports
1

Describe the Bug

Dev Container Features Not Installing Extensions

Summary

Dev container features are not properly installing extensions in Cursor IDE after a recent update. Extensions work when defined directly in devcontainer.json but fail when defined through dev container features.

Repository Structure

.devcontainer/
├── devcontainer.json
└── feature/
    ├── devcontainer-feature.json
    └── install.sh

Configuration Files

devcontainer.json

{
  "name": "feature",
  "image": "debian:11",
  "features": {
    "./feature": {}
  }
}

devcontainer-feature.json

{
  "id": "deno",
  "name": "Deno",
  "description": "A simple dev container feature that installs the Deno VS Code extension",
  "version": "1.0.0",
  "installsAfter": [],
  "customizations": {
    "vscode": {
      "extensions": ["denoland.vscode-deno"]
    }
  }
}

Issue Details

What Works :white_check_mark:

  • Extensions defined directly in devcontainer.json → Install successfully

What Doesn’t Work :cross_mark:

  • Extensions defined in dev container features → Fail to install

Steps to Reproduce

  1. Clone the test repository: GitHub - komondor/cursor-devcontainer-feature
  2. Open in Cursor IDE
  3. Try to build the dev container
  4. Observe that the Deno extension defined in the feature does not get installed

Expected Behavior

Dev container features should install VS Code extensions as specified in the devcontainer-feature.json file.

Additional Information

anysphere.remote-containers : 1.0.12

Operating System

MacOS

Current Cursor Version (Menu → About Cursor → Copy)

Version: 1.2.4
VSCode Version: 1.99.3
Commit: a8e95743c5268be73767c46944a71f4465d05c90
Date: 2025-07-10T16:53:59.659Z
Electron: 34.5.1
Chromium: 132.0.6834.210
Node.js: 20.19.0
V8: 13.2.152.41-electron.0
OS: Darwin arm64 24.3.0

Does this stop you from using Cursor

No - Cursor works, but with this issue

3

Hi @komondor , thank you for reporting this issue. We are looking into it and are working on a fix.

1 Like
4

Hi @komondor, could you try upgrading to version 1.0.14 of the Anysphere Remote Containers extension? This version fixes this bug where the customizations inside features were ignored.

5

Hi @ravirahman , it works ! Thanks