nit fixed

cli/cmd/version.go

@@ -5,17 +5,47 @@ package cmd
 
 import (
 	"fmt"
-
-	"github.com/spf13/cobra"
+	"runtime/debug"
 
 	"github.com/microsoft/retina/internal/buildinfo"
+	"github.com/spf13/cobra"
 )
 
 var version = &cobra.Command{
 	Use:   "version",
 	Short: "Show version",
-	Run: func(*cobra.Command, []string) {
-		fmt.Println(buildinfo.Version)
+	Run: func(cmd *cobra.Command, args []string) {
+		// Version is fetched from buildinfo package.
+		if buildinfo.Version != "" {
+			fmt.Println(buildinfo.Version)
+			return
+		}
+
+		// Fetch version from Build Settings.
+		const baseLine = "buildinfo.Version is not set successfully"
+
+		info, ok := debug.ReadBuildInfo()
+		if !ok {
+			fmt.Printf("%s, and BuildInfo is not available\n", baseLine)
+			return
+		}
+
+		var revision string
+		for _, setting := range info.Settings {
+			if setting.Key == "vcs.revision" {
+				revision = setting.Value
+				break
+			}
+		}
+
+		// If revision is available, show it.
+		if revision != "" {
+			fmt.Printf("%s, showing vcs.revision: %s\n", baseLine, revision)
+			return
+		}
+
+		// Revision is not available, raise error.
+		fmt.Printf("%s, and vcs.revision is not available\n", baseLine)
 	},
 }