Tidy mage package output: only display links on failure, fix failin…

…g fleet config embed (elastic#6547)

* Only log links on error.

* Fix failing to pack fleet config file.

dev-tools/mage/gotool/linkcheck.go

@@ -5,6 +5,8 @@
 package gotool
 
 import (
+	"fmt"
+
 	"github.com/magefile/mage/sh"
 )
 
@@ -15,7 +17,13 @@ var LinkCheck goLinkCheck = runGoLinkCheck
 
 func runGoLinkCheck(opts ...ArgOpt) error {
 	args := buildArgs(opts).build()
-	return sh.RunV("link-patrol", args...)
+	output, err := sh.Output("link-patrol", args...)
+	if err != nil {
+		fmt.Println(output)
+		return err
+	}
+
+	return nil
 }
 
 func (goLinkCheck) Path(path string) ArgOpt { return flagArgIf("-f", path) }

magefile.go

@@ -751,7 +751,7 @@ func BuildFleetCfg() error {
 	out := filepath.Join("internal", "pkg", "agent", "application", "configuration_embed.go")
 
 	fmt.Printf(">> BuildFleetCfg %s to %s\n", in, out)
-	return RunGo("run", goF, "--in", in, "--out", out)
+	return RunGo("run", goF, "--in", in, "--output", out)
 }
 
 // Enroll runs agent which enrolls before running.