Using VSCode DevContainers

I am trying to use the DevContainers extension of VSCode on NixOS. I’m managing VSCode and the extensions through home-manager. I’m able to build the container through VSCode, but when trying to edit or save new files in the editor once it’s connected to the container gives me the error:

Unable to write file 'vscode-remote://dev-container+2f746d702f626172666f6f/workspaces/barfoo/' (NoPermissions (FileSystemError): Error: EACCES: permission denied, open '/workspaces/barfoo/')

I think other people have had similar issues: Packaging request for VSCode Extension: Remote - Containers · Issue #182397 · NixOS/nixpkgs · GitHub

Is this something that requires a re-packaging of the extension?

Are you on unstable?

I was looking to use a VSCode Devcontainer on NixOS, but this extension seems to be missing on stable.

Is it possible to use only the extension from unstable?