Improve error message

Signed-off-by: Itxaka <[email protected]>

pkg/uki/common.go

@@ -296,5 +296,5 @@ func checkArtifactSignatureIsValid(fs v1.FS, artifact string, logger sdkTypes.Ka
 		}
 	}
 	// If we reach this point, we need to fail as we haven't matched anything, so default is to fail
-	return errors.New("not ok")
+	return fmt.Errorf("could not find a signature in EFIVars DB that matches the upgrade artifact")
 }

pkg/uki/upgrade.go

@@ -69,7 +69,9 @@ func (i *UpgradeAction) Run() (err error) {
 	if err != nil {
 		// Remove efi file to not occupy space and leave stuff around
 		_ = removeArtifactSetWithRole(i.cfg.Fs, constants.UkiEfiDir, UnassignedArtifactRole)
-		i.cfg.Logger.Logger.Error().Err(err).Msg("Checking signature")
+		i.cfg.Logger.Logger.Error().Err(err).Msg("Checking signature before upgrading")
+		i.cfg.Logger.Logger.Warn().Msg("Upgrade artifact signature does not match, upgrading to this source would result in an unbootable active system.\n" +
+			"Check the upgrade source and confirm that its signed with a valid key, that key is in the machine DB and it has not been blacklisted.")
 		return err
 	}