lint: fixes

go.mod

@@ -13,7 +13,7 @@ require (
 	go.opencensus.io v0.18.0 // indirect
 	golang.org/x/crypto v0.0.0-20181030102418-4d3f4d9ffa16
 	golang.org/x/exp v0.0.0-20181022080537-42ba7d4b6eb2
-	golang.org/x/net v0.0.0-20181102091132-c10e9556a7bc // indirect
+	golang.org/x/net v0.0.0-20181102091132-c10e9556a7bc
 	golang.org/x/oauth2 v0.0.0-20181102170140-232e45548389
 	golang.org/x/sys v0.0.0-20181031143558-9b800f95dbbc // indirect
 	google.golang.org/api v0.0.0-20181102150758-04bb50b6b83d

initialize.go

@@ -54,15 +54,15 @@ func Initialize(ctx context.Context, st storage.Storage, opt *NewRepositoryOptio
 	format := formatBlockFromOptions(opt)
 	masterKey, err := format.deriveMasterKeyFromPassword(password)
 	if err != nil {
-		return err
+		return fmt.Errorf("unable to derive master key: %v", err)
 	}
 
 	if err := encryptFormatBytes(format, repositoryObjectFormatFromOptions(opt), masterKey, format.UniqueID); err != nil {
-		return err
+		return fmt.Errorf("unable to encrypt format bytes: %v", err)
 	}
 
 	if err := writeFormatBlock(ctx, st, format); err != nil {
-		return err
+		return fmt.Errorf("unable to write format block: %v", err)
 	}
 
 	return nil

repository.go

@@ -26,16 +26,16 @@ type Repository struct {
 // Close closes the repository and releases all resources.
 func (r *Repository) Close(ctx context.Context) error {
 	if err := r.Manifests.Flush(ctx); err != nil {
-		return err
+		return fmt.Errorf("error flushing manifests: %v", err)
 	}
 	if err := r.Objects.Close(ctx); err != nil {
-		return err
+		return fmt.Errorf("error closing objects: %v", err)
 	}
 	if err := r.Blocks.Flush(ctx); err != nil {
-		return err
+		return fmt.Errorf("error closing blocks: %v", err)
 	}
 	if err := r.Storage.Close(ctx); err != nil {
-		return err
+		return fmt.Errorf("error closing storage: %v", err)
 	}
 	return nil
 }