db：createを実行すると、このエラーが発生します。
FATAL: Peer authentication failed for user "wandrr"
/home/jack/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/connection_adapters/postgresql_adapter.rb:1208:in `initialize'
/home/jack/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/connection_adapters/postgresql_adapter.rb:1208:in `new'
/home/jack/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/connection_adapters/postgresql_adapter.rb:1208:in `connect'
/home/jack/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/connection_adapters/postgresql_adapter.rb:326:in `initialize'
/home/jack/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/connection_adapters/postgresql_adapter.rb:28:in `new'
/home/jack/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/connection_adapters/postgresql_adapter.rb:28:in `postgresql_connection'
/home/jack/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:315:in `new_connection'
/home/jack/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:325:in `checkout_new_connection'
/home/jack/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:247:in `block (2 levels) in checkout'
/home/jack/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:242:in `loop'
/home/jack/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:242:in `block in checkout'
/home/jack/.rvm/rubies/ruby-1.9.3-p327/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
/home/jack/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:239:in `checkout'
/home/jack/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:102:in `block in connection'
/home/jack/.rvm/rubies/ruby-1.9.3-p327/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
/home/jack/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:101:in `connection'
/home/jack/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:410:in `retrieve_connection'
....Edit out 40 more of these warnings...
/home/jack/.rvm/gems/ruby-1.9.3-p327/bin/ruby_noexec_wrapper:14:in `eval'
/home/jack/.rvm/gems/ruby-1.9.3-p327/bin/ruby_noexec_wrapper:14:in `<main>'
Couldn't create database for {"adapter"=>"postgresql", "encoding"=>"unicode", "database"=>"wandrr_test", "pool"=>5, "username"=>"wandrr", "password"=>nil}
だから私はpg_hba.confを編集しなければならないことに気づきました。問題は...それが開かないことです。このファイルを使用する権限がないというメッセージが表示され続けます。では、どうすれば許可を得ることができますか？私はubuntu12.10とrails1.9.3とpostgres9.1を実行しています