[fix] : Fixed unbound variable

Author: Hayao0819

build.sh

@@ -519,6 +519,8 @@ prepare_build() {
         msg_warn "Re-run 'sudo ${0} ${DEFAULT_ARGUMENT} ${ARGUMENT} --nolog 2>&1 | tee ${logging}'"
         eval "sudo ${0} ${DEFAULT_ARGUMENT} ${ARGUMENT} --nolog 2>&1 | tee ${logging}"
         exit "${?}"
+    else
+        unset DEFAULT_ARGUMENT ARGUMENT
     fi
 
     # Set argument of pkglist.sh
@@ -1315,9 +1317,6 @@ if [[ ! "$(bash "${tools_dir}/channel.sh" --version "${alteriso_version}" ver "$
     fi
 fi
 
-
-unset DEFAULT_ARGUMENT ARGUMENT
-
 set -eu
 
 prepare_env