If you ever want to try the beta version of the Go extension which is built from the master, follow the below instructions:

• Download the vsix file from https://github.com/Microsoft/vscode-go/releases/tag/latest
• Run code --install-extension Go-latest.vsix
• Reload VS Code

Note: When when you install a beta version, there is no auto-update mechanism where a newer beta version will get installed automatically.