--- a/test/make/configure.vm	Sun Dec 15 14:50:19 2024 +0100
+++ b/test/make/configure.vm	Sun Dec 15 14:56:05 2024 +0100
@@ -646,6 +646,11 @@
             DEPENDENCIES_FAILED="option '${opt.argument}' $DEPENDENCIES_FAILED"
         fi
     #end
+    else
+        echo
+        echo "Invalid option value - usage:"
+        echo "  --${opt.argument}=${opt.valuesString}"
+        abort_configure
     fi
 fi
 #end