Currently VSCode is implementing it's own solution for preventing a second instance from starting. Electron provides API to do the same but there are differences: https://github.com/electron/electron/blob/7-1-x/docs/api/app.md#apprequestsingleinstancelock

Things we need:

• pass the process environment over (second-instance event should pass ENV of requester electron/electron#18434)
• communicate between second and first instance to support code --status [1]

[1] code --status will print information about the active window in the first instance to the console of the second instance and thus requires access to the workspace, including remote scenarios.