fix: show module version for go install builds

cmd/vanityrig/interactive.go

@@ -25,7 +25,7 @@ func runInteractive(patterns []string, out string, mode vanity.MatchMode, rate f
 		Rate:       rate,
 		StopAfter:  stopAfter,
 		EnginePath: enginePath,
-		Version:    version,
+		Version:    resolveVersion(),
 	})
 
 	p := tea.NewProgram(m, tea.WithAltScreen(), tea.WithMouseCellMotion())

cmd/vanityrig/main.go

@@ -12,17 +12,33 @@ import (
 	"flag"
 	"fmt"
 	"os"
+	"runtime/debug"
 	"strings"
 	"time"
 
 	"github.com/bytestrix/vanityrig/internal/vanity"
 )
 
 // version is set at build time via -ldflags "-X main.version=...". Release
-// binaries get their real tag; anything built with plain `go build` or
-// `go install` stays "dev" rather than lying about which release it is.
+// binaries get their real tag. Plain `go install ...@vX.Y.Z` leaves this as
+// "dev"; resolveVersion then falls back to module build info.
 var version = "dev"
 
+func resolveVersion() string {
+	if version != "" && version != "dev" {
+		return version
+	}
+	info, ok := debug.ReadBuildInfo()
+	if !ok || info == nil {
+		return version
+	}
+	v := info.Main.Version
+	if v == "" || v == "(devel)" {
+		return version
+	}
+	return v
+}
+
 const usage = `vanityrig - find a vanity .onion address
 
 Usage:
@@ -79,7 +95,7 @@ func run(args []string) int {
 		return 0
 	}
 	if args[0] == "-version" || args[0] == "--version" {
-		fmt.Println("vanityrig", version)
+		fmt.Println("vanityrig", resolveVersion())
 		return 0
 	}
 

cmd/vanityrig/version_test.go

@@ -0,0 +1,18 @@
+package main
+
+import "testing"
+
+func TestResolveVersionFallsBackToDevWithoutModuleVersion(t *testing.T) {
+	// Under `go test`, ReadBuildInfo reports "(devel)" for the main module, so
+	// resolveVersion must keep the ldflags/default value.
+	old := version
+	t.Cleanup(func() { version = old })
+	version = "dev"
+	if got := resolveVersion(); got != "dev" {
+		t.Fatalf("resolveVersion() = %q, want %q", got, "dev")
+	}
+	version = "1.2.3"
+	if got := resolveVersion(); got != "1.2.3" {
+		t.Fatalf("resolveVersion() with ldflags = %q, want 1.2.3", got)
+	}
+}