database/worker: Remove useless log message

database/package.go

@@ -283,7 +283,6 @@ func FindOnePackage(OS, name string, version types.Version, selectedFields []str
 // FindAllPackagesByNodes finds and returns all packages given by their nodes, selecting the specified fields
 func FindAllPackagesByNodes(nodes []string, selectedFields []string) ([]*Package, error) {
 	if len(nodes) == 0 {
-		log.Warning("could not FindAllPackagesByNodes with an empty nodes array.")
 		return []*Package{}, nil
 	}
 

worker/worker.go

@@ -23,11 +23,11 @@ import (
 	"os"
 	"strings"
 
-	"github.com/coreos/pkg/capnslog"
 	"github.com/coreos/clair/database"
 	"github.com/coreos/clair/utils"
 	cerrors "github.com/coreos/clair/utils/errors"
 	"github.com/coreos/clair/worker/detectors"
+	"github.com/coreos/pkg/capnslog"
 )
 
 const (
@@ -125,7 +125,11 @@ func detectContent(ID, path string, parent *database.Layer) (OS string, installe
 	if err != nil {
 		return
 	}
-	log.Debugf("layer %s: OS is %s.", ID, OS)
+	if OS != "" {
+		log.Debugf("layer %s: OS is %s.", ID, OS)
+	} else {
+		log.Debugf("layer %s: OS is unknown.", ID)
+	}
 
 	packageList, err := detectors.DetectPackages(data)
 	if err != nil {