Do not override defaults with blanks

[kke]

Check the values from debug.ReadBuildInfo() before overriding the versioninfo.* variables in init functions.

This makes it easier/possible to override them using the -X LD_FLAGS when building from a Makefile or such:

LD_FLAGS = -s -w -X github.com/carlmjohnson/versioninfo.Revision=$(GIT_COMMIT) -X github.com/carlmjohnson/versioninfo.Version=$(BUILD_VERSION)
BUILD_FLAGS = -ldflags "$(LD_FLAGS)"

This should still maintain the existing functionality when using go install repo/tool@version and possibly partly fix it if some of the keys are for some reason blank and would overwrite the defaults set in variables.go.

[earthboundkid]

Thanks! I’m on mobile, but I’ll tag a version when I get back to a real computer.

[arnested]

This is really useful!

Although it appears to be only working when building, main.go and not .

With a minimal example:

package main

import (
	"fmt"

	"github.com/carlmjohnson/versioninfo"
)

func main() {
	a := versioninfo.Short()
	fmt.Println(a)
}

$ go run -ldflags='-X github.com/carlmjohnson/versioninfo.Version=v1.2.3' main.go 
v1.2.3
$ go run -ldflags='-X github.com/carlmjohnson/versioninfo.Version=v1.2.3' .
devel

I don't think this is an error in this change or this package. I guess this is Go's compiler or linker behaving in a way I don't understand 😄

[arnested]

Or... This appears to resolve the problem. I'm not sure if this is the right fix (it's getting late at my localtime).

diff --git a/legacy.go b/legacy.go
index b8c5fac..1433f46 100644
--- a/legacy.go
+++ b/legacy.go
@@ -9,7 +9,7 @@ func init() {
        if !ok {
                return
        }
-       if info.Main.Version != "" {
+       if info.Main.Version != "" && info.Main.Version != "(devel)" {
                Version = info.Main.Version
        }
 }

[earthboundkid]

I haven't had time to look at this, so I added a tracker for it: #12