Use RSpec's let feature instead of instance variables.

spec/spec_helper.rb

@@ -8,24 +8,16 @@ require 'construct'
 RSpec.configure do |config|
   config.include Construct::Helpers
 
-  config.before do
-    @user_dir = create_construct
-    ENV['HOME'] = @user_dir.to_s
+  config.before { ENV['HOME'] = home.to_s }
 
-    @repos_dir = @user_dir.directory(".homesick/repos")
-    homesick.stub!(:repos_dir).and_return(@repos_dir)
-  end
-
-  config.after do
-    @user_dir.destroy!
-  end
+  config.before { silence! }
 
   def silence!
     homesick.stub(:say_status)
   end
 
   def given_castle(name, path=name)
-    @repos_dir.directory(path) do |castle|
+    castles.directory(path) do |castle|
       Dir.chdir(castle) do
         system "git init >/dev/null 2>&1"
         system "git remote add origin git://github.com/technicalpickles/#{name}.git >/dev/null 2>&1"