Replace embedding version info with buildinfo (wtfutil#1328)

* Replace embedding version info with buildinfo

* Less verbosity

Makefile

@@ -100,7 +100,7 @@ install:
 	@echo "$$HEADER"
 	@echo "Installing ${APP} with ${GOVERS}..."
 	@go clean
-	@go install -ldflags="-s -w -X main.version=$(shell git describe --always --abbrev=6) -X main.date=$(shell date +%FT%T%z)"
+	@go install -ldflags="-s -w"
 	@mv $(GOBIN)/wtf $(GOBIN)/${APP}
 	$(eval INSTALLPATH = $(shell which ${APP}))
 	@echo "${APP} installed into ${INSTALLPATH}"

flags/flags.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"runtime/debug"
 	"strings"
 
 	"github.com/chzyer/readline"
@@ -54,13 +55,23 @@ func (flags *Flags) ConfigFilePath() string {
 
 // RenderIf displays special-case information based on the flags passed
 // in, if any flags were passed in
-func (flags *Flags) RenderIf(version, date string, config *config.Config) {
+func (flags *Flags) RenderIf(config *config.Config) {
 	if flags.HasModule() {
 		help.Display(flags.Module, config)
 		os.Exit(0)
 	}
 
 	if flags.HasVersion() {
+		info, _ := debug.ReadBuildInfo()
+		version := "dev"
+		date := "now"
+		for _, setting := range info.Settings {
+			if setting.Key == "vcs.revision" {
+				version = setting.Value
+			} else if setting.Key == "vcs.time" {
+				date = setting.Value
+			}
+		}
 		fmt.Printf("%s (%s)\n", version, date)
 		os.Exit(0)
 	}

main.go

@@ -21,11 +21,6 @@ import (
 	"github.com/wtfutil/wtf/wtf"
 )
 
-var (
-	date    = "dev"
-	version = "dev"
-)
-
 /* -------------------- Main -------------------- */
 
 func main() {
@@ -41,7 +36,7 @@ func main() {
 
 	wtf.SetTerminal(config)
 
-	flags.RenderIf(version, date, config)
+	flags.RenderIf(config)
 
 	if flags.Profile {
 		defer profile.Start(profile.MemProfile).Stop()