Determine version via go 1.18's buildinfo

This makes it possible to use go install with the github URL and end up with an
executable that knows it's version.

At the moment we still set the version when building via the build-release
script.

rolling-shutter/Makefile

@@ -6,9 +6,7 @@ BINDIR		?= ./bin
 EXECUTABLE	?= ${BINDIR}/rolling-shutter
 
 build:
-	@VERSION=`git describe --tags --always --abbrev=4 --dirty --match 'rolling-shutter/v*' | sed -e s#^rolling-shutter/##`; \
-	echo "Building ${EXECUTABLE} $${VERSION}"; \
-	${GO} build ${GOFLAGS} -o ${EXECUTABLE} -ldflags "-X github.com/shutter-network/rolling-shutter/rolling-shutter/cmd/shversion.version=$${VERSION}"; \
+	${GO} build ${GOFLAGS} -o ${EXECUTABLE}
 
 wasm:
 	GOARCH=wasm GOOS=js ${GO} build ${GOFLAGS} -o ${BINDIR}/shcrypto.wasm ./shcryptowasm/main_wasm.go

rolling-shutter/cmd/shversion/shversion.go

@@ -5,12 +5,28 @@ package shversion
 import (
 	"fmt"
 	"runtime"
+	"runtime/debug"
 )
 
-var version string = "(unknown)"
+var version string
 
 // Version returns shuttermint's version string.
 func Version() string {
+	if version == "" {
+		info, ok := debug.ReadBuildInfo()
+		if ok {
+			version = info.Main.Version
+			if version == "(devel)" {
+				for _, s := range info.Settings {
+					if s.Key == "vcs.revision" {
+						version = fmt.Sprintf("(devel-%s)", s.Value)
+						break
+					}
+				}
+			}
+		}
+	}
+
 	var raceinfo string
 	if raceDetectorEnabled {
 		raceinfo = ", race detector enabled"