diff --git a/cmd/thanos/tools_test.go b/cmd/thanos/tools_test.go
index 7d39abda55..2e3e3d9329 100644
--- a/cmd/thanos/tools_test.go
+++ b/cmd/thanos/tools_test.go
@@ -4,6 +4,7 @@
 package main
 
 import (
+	"fmt"
 	"os"
 	"testing"
 
@@ -49,6 +50,13 @@ func Test_CheckRules_Glob(t *testing.T) {
 	// Unreadble path
 	files = &[]string{"./testdata/rules-files/unreadable_valid.yaml"}
 	filename := (*files)[0]
+	// TODO: debugging
+	err := os.Chmod(filename, 0000)
+	if err != nil {
+		logger.Log("err", err)
+		fmt.Println("XXX", err)
+	}
+
 	testutil.Ok(t, os.Chmod(filename, 0000), "failed to change file permissions of %s to 0000", filename)
 	testutil.NotOk(t, checkRulesFiles(logger, files), "expected err for file %s", files)
 	testutil.Ok(t, os.Chmod(filename, 0777), "failed to change file permissions of %s to 0777", filename)