v0.22.1 cli flag and behavior, and test output improvement

internal/version/version.go

@@ -1,6 +1,9 @@
 package version
 
-import "fmt"
+import (
+	"fmt"
+	"runtime/debug"
+)
 
 var (
 	// Version is the application version, set at compile time via -ldflags
@@ -11,11 +14,28 @@ var (
 	BuildTime = "unknown"
 )
 
+// init fills what -ldflags left unset from the build info: `go install
+// module@version` stamps the module version, a build in a checkout the commit.
+func init() {
+	info, ok := debug.ReadBuildInfo()
+	if !ok {
+		return
+	}
+	if v := info.Main.Version; Version == "dev" && v != "" && v != "(devel)" {
+		Version = v
+	}
+	for _, s := range info.Settings {
+		switch {
+		case s.Key == "vcs.revision" && GitCommit == "unknown":
+			GitCommit = s.Value[:min(len(s.Value), 12)]
+		case s.Key == "vcs.time" && BuildTime == "unknown":
+			BuildTime = s.Value
+		}
+	}
+}
+
 // String returns a detailed, formatted version string including commit and build time
 func String() string {
-	if Version == "dev" {
-		return fmt.Sprintf("dev (commit: %s, built: %s)", GitCommit, BuildTime)
-	}
 	return fmt.Sprintf("%s (commit: %s, built: %s)", Version, GitCommit, BuildTime)
 }