The 2.0 release introduces a new tool, SourceKite, as the interface to SourceKit library. Since the Swift ABI is not stable, you need to build it if you want to use SDE. Go to SourceKite for further instructions. Also because the Swift ABI is not stable, you may find that the Hover Help or the Code Completion don't display the right information after you upgrade your Swift toolchain. This is because the SourceKit library you linked with the SourceKite tool can't understand the sources or binaries of your project. To fix this, rebuild your project and restart vscode.