Fix git-fetch and brctl doc

README.md

@@ -79,5 +79,5 @@ If you have a runaway `lxc-start` command, just use `kill -9` on it.
 
 The machine configuration requires access to br0 and assumes that the host address is 10.0.2.2:
 
-    sudo brctl add br0
+    sudo brctl addbr br0
     sudo ifconfig br0 10.0.2.2/24 up

bin/gbuild

@@ -193,7 +193,7 @@ build_desc["remotes"].each do |remote|
       system!("git init inputs/#{dir}")
       system!("cd inputs/#{dir} && git remote add origin #{sanitize_path(remote["url"], remote["url"])}")
   end
-  system!("cd inputs/#{dir} && git fetch --tags")
+  system!("cd inputs/#{dir} && git fetch && git fetch --tags")
   commit = sanitize(remote["commit"], remote["commit"])
   commit = `cd inputs/#{dir} && git log --format=%H -1 #{commit}`.strip
   system!("cd inputs/#{dir} && git checkout -q #{commit}")