diff --git a/darwin-configuration.nix b/darwin-configuration.nix
index 0dda1ed..19ced6c 100644
--- a/darwin-configuration.nix
+++ b/darwin-configuration.nix
@@ -25,17 +25,17 @@
 
   nix.settings = {
     auto-optimise-store = true;
-    substituters =  lib.mkForce [ 
-      "https://mirrors.ustc.edu.cn/nix-channels/store"  # 中科大
-      "https://mirrors.tuna.tsinghua.edu.cn/nix-channels/store"  #清华
-      "https://mirrors.bfsu.edu.cn/nix-channels/store"  # 北外
+    substituters = lib.mkForce [
+      "https://mirrors.ustc.edu.cn/nix-channels/store" # 中科大
+      "https://mirrors.tuna.tsinghua.edu.cn/nix-channels/store" #清华
+      "https://mirrors.bfsu.edu.cn/nix-channels/store" # 北外
       "https://mirror.sjtu.edu.cn/nix-channels/store" #交大
       "https://cache.nixos.org/"
     ];
   };
 
   # Create /etc/zshrc that loads the nix-darwin environment.
-  programs.zsh.enable = true;  # default shell on catalina
+  programs.zsh.enable = true; # default shell on catalina
   # programs.fish.enable = true;
 
   # Used for backwards compatibility, please read the changelog before changing.
diff --git a/home.nix b/home.nix
index c99535b..87398f2 100644
--- a/home.nix
+++ b/home.nix
@@ -1,4 +1,4 @@
-{pkgs, config, ...}: {
+{ pkgs, config, ... }: {
   home = {
     stateVersion = "23.05";
     homeDirectory = "/Users/tonychyi";
@@ -17,7 +17,8 @@
       kubectl
       kubernetes-helm
       arduino-cli
-      obs-studio
+      qemu
+      #obs-studio
     ];
 
     shellAliases = {
@@ -27,7 +28,7 @@
       pip = "pip3";
       ls = "ls --color=auto";
       cat = "bat -p --paging=never -u";
-      diff="icdiff";
+      diff = "icdiff";
     };
 
     sessionVariables = {
@@ -43,7 +44,7 @@
       "$GOPATH/bin"
     ];
   };
-  
+
   programs = {
     home-manager.enable = true;
     timidity.enable = true;