about/help: provide more diagnostic information

Provide by default information like Go version, commit hash,
OS which is usually neglected during bug reports and has
to be reminded to the issue reporters.

src/help.go

@@ -16,6 +16,8 @@ package drive
 
 import (
 	"fmt"
+
+	"github.com/odeke-em/xon/pkger/src"
 )
 
 const (
@@ -45,10 +47,11 @@ const (
 	UnpubKey      = "unpub"
 	VersionKey    = "version"
 
-	ForceKey     = "force"
-	QuietKey     = "quiet"
-	QuitShortKey = "q"
-	QuitLongKey  = "quit"
+	ForceKey         = "force"
+	QuietKey         = "quiet"
+	QuitShortKey     = "q"
+	QuitLongKey      = "quit"
+	DriveRepoRelPath = "github.com/odeke-em/drive"
 )
 
 const (
@@ -184,7 +187,12 @@ func ShowAllDescriptions() {
 }
 
 func PrintVersion() {
-	fmt.Printf("drive version %s\n", Version)
+	fmt.Printf("drive version %s", Version)
+	pkgInfo, err := pkger.Recon(DriveRepoRelPath)
+	if err == nil && pkgInfo != nil {
+		fmt.Printf("\n%s", pkgInfo)
+	}
+	fmt.Println()
 }
 
 func ShowDescription(topic string) {