Avoids missing version description when using go install (#600)

main.go

@@ -6,6 +6,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"runtime/debug"
 	"strings"
 
 	"github.com/fatih/color"
@@ -213,13 +214,30 @@ func init() {
 
 	// Output build info (version, commit, date and builtBy)
 	if versionFlag {
-		fmt.Printf(
-			"Version:\t%s\nCommit:\t\t%s\nBuilt\t\t%s by %s\n",
-			version,
-			commit,
-			date,
-			builtBy,
-		)
+		var buildInfo string
+		if date != "unknown" && builtBy != "unknown" {
+			buildInfo = fmt.Sprintf("Built\t\t%s by %s\n", date, builtBy)
+		}
+
+		if commit != "none" {
+			buildInfo = fmt.Sprintf("Commit:\t\t%s\n%s", commit, buildInfo)
+		}
+
+		if version == "dev" {
+			bi, ok := debug.ReadBuildInfo()
+			if ok {
+				version = bi.Main.Version
+				if strings.HasPrefix(version, "v") {
+					version = bi.Main.Version[1:]
+				}
+				if len(buildInfo) == 0 {
+					fmt.Printf("version %s\n", version)
+					os.Exit(0)
+				}
+			}
+		}
+
+		fmt.Printf("Version:\t%s\n%s", version, buildInfo)
 		os.Exit(0)
 	}
 }