build: tolerate build without git repo

Signed-off-by: tison <[email protected]>

Author: tisonkun

Makefile

@@ -6,7 +6,7 @@ DIR_SRC=./cmd/answer
 DOCKER_CMD=docker
 
 GO_ENV=CGO_ENABLED=0 GO111MODULE=on
-Revision=$(shell git rev-parse --short HEAD)
+Revision=$(shell git rev-parse --short HEAD 2&>/dev/null || echo "")
 GO_FLAGS=-ldflags="-X github.com/apache/incubator-answer/cmd.Version=$(VERSION) -X 'github.com/apache/incubator-answer/cmd.Revision=$(Revision)' -X 'github.com/apache/incubator-answer/cmd.Time=`date +%s`' -extldflags -static"
 GO=$(GO_ENV) $(shell which go)
 

cmd/main.go

@@ -44,9 +44,10 @@ var (
 	// Version is the version of the project
 	Version = "0.0.0"
 	// Revision is the git short commit revision number
-	Revision = "-"
+	// If built without a Git repository, this field will be empty.
+	Revision = ""
 	// Time is the build time of the project
-	Time = "-"
+	Time = ""
 	// GoVersion is the go version of the project
 	GoVersion = "1.19"
 	// log level