Anysphere Dev Containers extension not compatible with existing devcontainer.json

Support Bug Reports
1

Edit: Updated this post after I realized the bug seems to specifically be related to specifying vscode in the customizations section.

Describe the Bug

In short, the Anysphere Dev Containers extension appears to crash or fail to start the dev container if the dev container customizations block includes vscode.

Steps to Reproduce

Create a new dev container config (or reuse an existing one). Ensure you have a “customizations” block as follows:

  // ... 
  "customizations": {
    "vscode": {
      "extensions": [
          // ...
      ]
    }
  }
  // ...

When you attempt to build/rebuild the dev container, it will get most of the way through the process and fail at the end with an error that doesn’t really explain the problem. The most “helpful” part of the logs I found was:

Ignoring option 'install-extension': Value must not be empty.
Ignoring option 'c': not supported for server.
Ignoring option 'w': not supported for server.
Ignoring option 'e': not supported for server.
Ignoring option 'i': not supported for server.
Ignoring option 'j': not supported for server.
Ignoring option 'a': not supported for server.
Ignoring option 'n': not supported for server.
Ignoring option 's': not supported for server.
Ignoring option 'm': not supported for server.
1.2.4
a8e95743c5268be73767c46944a71f4465d05c90
arm64

Expected Behavior

I expected the extension to be a drop-in replacement for Microsoft’s VSCode dev containers extension, respecting the same settings and/or allowing for a cursor customization block like other tools (Codespaces, for example) support.

Operating System

MacOS

Current Cursor Version (Menu → About Cursor → Copy)

Version: 1.2.4 (Universal)
VSCode Version: 1.99.3
Commit: a8e95743c5268be73767c46944a71f4465d05c90
Date: 2025-07-10T16:55:16.443Z
Electron: 34.5.1
Chromium: 132.0.6834.210
Node.js: 20.19.0
V8: 13.2.152.41-electron.0
OS: Darwin arm64 24.5.0

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

3

Hi @CS-5 , could you share your devcontainer.json file and the logs from the “Remote - Dev Container” output window so we can take a closer look?

4

I will try and come up with a minimal repro. Currently the only repro I have is with our fairly complex internal devcontainer.json, including several pre/post start scripts, dev container features, and more.

I believe I’ve isolated the problem to the syntax of prefixing extensions with - to remove them in the customizations.vscode.extensions array. For example, our extensions list is as follows:

      "extensions": [
        "esbenp.prettier-vscode",
        "dbaeumer.vscode-eslint",
        "bradlc.vscode-tailwindcss",
        "golang.go",
        "ms-vscode-remote.remote-containers",
        "ms-vscode.remote-explorer",
        "mtxr.sqltools",
        "mtxr.sqltools-driver-pg",
        "-cweijan.vscode-redis-client",
        "-vscjava.vscode-java-pack",
        "ms-python.mypy-type-checker",
        "ms-python.python",
        "ms-python.debugpy",
        "charliermarsh.ruff",
        "-ms-python.vscode-pylance"
      ],

Notice how the Ignoring option... errors spell out cweijan, which is the first removed extension in the block above.

Either way, I’ll work on creating a reliable repro this week and will share the results.

6

Hi @CS-5, thank you for this. Yes, this is an issue in our extension; we are working on an update to support the “opt out” syntax (with the leading “-”). For now, could you comment out those lines from the list, and manually uninstall them once the container loads?

7

Hi @CS-5, we fixed this issue in version 1.0.16 of the Remote Containers extension. Could you try upgrading the extension?

8

It looks like that update fixed this issue, thanks for getting that addressed quickly!