perform_upgrade

lib/self-upgrade.bash

@@ -52,7 +52,11 @@ function system_upgrade {
 }
 
 function perform_upgrade {
-  sudo_root
+  if sudo_root; then
+    :
+  else
+    builtin exit 1
+  fi
   local backup="$MIAOU_BASH_DIR".before_upgrade
   sudo mv "$MIAOU_BASH_DIR" "$backup"
   curl -s --output /tmp/miaou-bash-install.sh "$INSTALL_URL"