--- a/prosodyctl	Sun Apr 02 10:40:48 2023 +0200
+++ b/prosodyctl	Fri Apr 07 15:54:59 2023 +0100
@@ -669,7 +669,7 @@
 			end
 			os.exit(0, true); -- :)
 		else
-			show_message("Failed to execute command: "..error_messages[ret]);
+			show_message("Failed to execute command: %s", error_messages[ret]);
 			os.exit(1); -- :(
 		end
 	end