get chris's nits.

main.go

@@ -75,10 +75,13 @@ func realMain() int {
 
 		// Enable checkpoint for panic reporting
 		config, err := loadConfig()
-		if err == nil {
-			if !config.DisableCheckpoint {
-				packer.CheckpointReporter.Enable(config.DisableCheckpointSignature)
-			}
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Couldn't load config: %s", err)
+			return 1
+		}
+
+		if !config.DisableCheckpoint {
+			packer.CheckpointReporter.Enable(config.DisableCheckpointSignature)
 		}
 
 		// Create the configuration for panicwrap and wrap our executable

packer/telemetry.go

@@ -2,7 +2,6 @@ package packer
 
 import (
 	"context"
-	"fmt"
 	"log"
 	"os"
 	"path/filepath"
@@ -56,7 +55,7 @@ func (c *CheckpointTelemetry) Enable(disableSignature bool) {
 func (c *CheckpointTelemetry) baseParams(prefix string) *checkpoint.ReportParams {
 	version := packerVersion.Version
 	if packerVersion.VersionPrerelease != "" {
-		version += fmt.Sprintf("-%s", packerVersion.VersionPrerelease)
+		version += "-" + packerVersion.VersionPrerelease
 	}
 
 	return &checkpoint.ReportParams{
@@ -69,9 +68,6 @@ func (c *CheckpointTelemetry) baseParams(prefix string) *checkpoint.ReportParams
 	}
 }
 
-func (c *CheckpointTelemetry) log(m string, args ...interface{}) {
-}
-
 func (c *CheckpointTelemetry) ReportPanic(m string) error {
 	if !c.enabled {
 		return nil