title: db:migrate hangs on simple migration
body: <p>I am using PostgreSQL, Rails 3.1.3 and Ruby 1.9.3. I am struggling to use <code>db:migrate</code> as outlined <a href="http://ruby.railstutorial.org/chapters/modeling-and-viewing-users-one#code%3aemail_uniqueness_index" rel="noreferrer">here</a>.</p>
  
  <p>This is what I am seeing in the terminal: </p>
  
  <pre><code>funkdified@funkdified-laptop:~/railsprojects/hartl$ bundle exec rake db:migrate --trace 
  ** Invoke db:migrate (first_time) 
  ** Invoke environment (first_time) 
  ** Execute environment 
  ** Invoke db:load_config (first_time) 
  ** Invoke rails_env (first_time) 
  ** Execute rails_env 
  ** Execute db:load_config 
  ** Execute db:migrate 
  == AddEmailUniquenessIndex: migrating ======================================== 
  -- add_index(:users, :email, {:unique=&gt;true})
  </code></pre>
  
  <p>and then the code hangs at this point. Any ideas why?</p>
  
  <p>From: development.log </p>
  
  <pre><code>[1m[36m (0.1ms)[0m [1mSHOW search_path[0m 
  [1m[35m (0.5ms)[0m SELECT "schema_migrations"."version" FROM "schema_migrations"
  Migrating to CreateUsers (20120124022843) 
  Migrating to AddEmailUniquenessIndex (20120124093922) 
  [1m[36m (0.1ms)[0m [1mBEGIN[0m 
  [1m[35m (3.6ms)[0m SELECT distinct i.relname, d.indisunique, d.indkey, t.oid 
  FROM pg_class t 
  INNER JOIN pg_index d ON t.oid = d.indrelid 
  INNER JOIN pg_class i ON d.indexrelid = i.oid 
  WHERE i.relkind = 'i' 
  AND d.indisprimary = 'f' 
  AND t.relname = 'users' 
  AND i.relnamespace IN (SELECT oid FROM pg_namespace WHERE nspname = ANY (current_schemas(false)) ) 
  ORDER BY i.relname
  </code></pre>