From dca200c2e91121426fec7e21d6ee091419eb9200 Mon Sep 17 00:00:00 2001
From: Alexander Neumann <alexander@bumpern.de>
Date: Tue, 25 Aug 2015 22:07:52 +0200
Subject: [PATCH 1/3] build.go: Make `-ldflags` compatible to Go 1.5

This change uses the old syntax (-ldflags "-X foo bar") for Go <= 1.4
and the new syntax for (-ldflags "-X foo=bar") for Go 1.5 (without a
warning).
---
 build.go | 28 ++++++++++++++++++++++++++--
 1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/build.go b/build.go
index 05c930ae3..d14566fc2 100644
--- a/build.go
+++ b/build.go
@@ -229,6 +229,27 @@ func gitVersion() string {
 	return version
 }
 
+// Constants represents a set constants set in the final binary to the given
+// value.
+type Constants map[string]string
+
+// LDFlags returns the string that can be passed to go build's `-ldflags`.
+func (cs Constants) LDFlags() string {
+	l := make([]string, 0, len(cs))
+
+	if strings.HasPrefix(runtime.Version(), "go1.5") {
+		for k, v := range cs {
+			l = append(l, fmt.Sprintf(`-X "%s=%s"`, k, v))
+		}
+	} else {
+		for k, v := range cs {
+			l = append(l, fmt.Sprintf(`-X %q %q`, k, v))
+		}
+	}
+
+	return strings.Join(l, " ")
+}
+
 func main() {
 	buildTags := []string{}
 
@@ -307,10 +328,13 @@ func main() {
 	}
 	version := getVersion()
 	compileTime := time.Now().Format(timeFormat)
-	ldflags := fmt.Sprintf("-s -X main.compiledAt %q", compileTime)
+	constants := Constants{`main.compiledAt`: compileTime}
 	if version != "" {
-		ldflags = fmt.Sprintf("%s -X main.version %q", ldflags, version)
+		constants["main.version"] = version
 	}
+	ldflags := "-s " + constants.LDFlags()
+	fmt.Printf("ldflags: %s\n", ldflags)
+
 	args := []string{
 		"-tags", strings.Join(buildTags, " "),
 		"-ldflags", ldflags,

From 4c47c2b2c9fda4d8ec59d6131aefa3723b335390 Mon Sep 17 00:00:00 2001
From: Alexander Neumann <alexander@bumpern.de>
Date: Wed, 26 Aug 2015 20:03:16 +0200
Subject: [PATCH 2/3] Address code review comments

---
 build.go | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/build.go b/build.go
index d14566fc2..fe943d9e2 100644
--- a/build.go
+++ b/build.go
@@ -229,8 +229,8 @@ func gitVersion() string {
 	return version
 }
 
-// Constants represents a set constants set in the final binary to the given
-// value.
+// Constants represents a set of constants that are set in the final binary to
+// the given value via compiler flags.
 type Constants map[string]string
 
 // LDFlags returns the string that can be passed to go build's `-ldflags`.
@@ -318,7 +318,7 @@ func main() {
 				die("remove GOPATH at %s failed: %v\n", err)
 			}
 		} else {
-			fmt.Printf("leaving temporary GOPATH at %v\n", gopath)
+			verbosePrintf("leaving temporary GOPATH at %v\n", gopath)
 		}
 	}()
 
@@ -333,7 +333,7 @@ func main() {
 		constants["main.version"] = version
 	}
 	ldflags := "-s " + constants.LDFlags()
-	fmt.Printf("ldflags: %s\n", ldflags)
+	verbosePrintf("ldflags: %s\n", ldflags)
 
 	args := []string{
 		"-tags", strings.Join(buildTags, " "),

From a54f9715b1fe1f8234bf280569b59aaba4516df5 Mon Sep 17 00:00:00 2001
From: Alexander Neumann <alexander@bumpern.de>
Date: Wed, 26 Aug 2015 20:03:26 +0200
Subject: [PATCH 3/3] Add "build: " prefix to verbose messages

---
 build.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/build.go b/build.go
index fe943d9e2..b6cfbcd55 100644
--- a/build.go
+++ b/build.go
@@ -159,7 +159,7 @@ func verbosePrintf(message string, args ...interface{}) {
 		return
 	}
 
-	fmt.Printf(message, args...)
+	fmt.Printf("build: "+message, args...)
 }
 
 // cleanEnv returns a clean environment with GOPATH and GOBIN removed (if