"getaddrinfo: nom ou service inconnu" lorsque rake db: migrate

# rake db:migrate --trace 
(in /www/rails_app) 
** Invoke db:migrate (first_time) 
** Invoke environment (first_time) 
** Execute environment 
** Execute db:migrate 
rake aborted! 
getaddrinfo: Name or service not known 
/usr/local/lib/ruby/gems/1.9.1/gems/postgres-pr-0.6.3/lib/postgres-pr/connection.rb:165:in `initialize' 
/usr/local/lib/ruby/gems/1.9.1/gems/postgres-pr-0.6.3/lib/postgres-pr/connection.rb:165:in `new' 
/usr/local/lib/ruby/gems/1.9.1/gems/postgres-pr-0.6.3/lib/postgres-pr/connection.rb:165:in `establish_connection' 
/usr/local/lib/ruby/gems/1.9.1/gems/postgres-pr-0.6.3/lib/postgres-pr/connection.rb:51:in `initialize' 
/usr/local/lib/ruby/gems/1.9.1/gems/postgres-pr-0.6.3/lib/postgres-pr/postgres-compat.rb:23:in `new' 
/usr/local/lib/ruby/gems/1.9.1/gems/postgres-pr-0.6.3/lib/postgres-pr/postgres-compat.rb:23:in `initialize' 
/getweb/ebr/vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb:939:in `new' 
/getweb/ebr/vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb:939:in `connect' 
/getweb/ebr/vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb:217:in `initialize' 
/getweb/ebr/vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb:37:in `new' 
/getweb/ebr/vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb:37:in `postgresql_connection' 
/getweb/ebr/vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb:223:in `new_connection' 
/getweb/ebr/vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb:245:in `checkout_new_connection' 
/getweb/ebr/vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb:188:in `block (2 levels) in checkout' 
/getweb/ebr/vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb:184:in `loop' 
/getweb/ebr/vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb:184:in `block in checkout' 
/usr/local/lib/ruby/1.9.1/monitor.rb:190:in `mon_synchronize' 
/getweb/ebr/vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb:183:in `checkout' 
/getweb/ebr/vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb:98:in `connection' 
/getweb/ebr/vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb:326:in `retrieve_connection' 
/getweb/ebr/vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb:123:in `retrieve_connection' 
/getweb/ebr/vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb:115:in `connection' 
/getweb/ebr/vendor/rails/activerecord/lib/active_record/migration.rb:440:in `initialize' 
/getweb/ebr/vendor/rails/activerecord/lib/active_record/migration.rb:401:in `new' 
/getweb/ebr/vendor/rails/activerecord/lib/active_record/migration.rb:401:in `up' 
/getweb/ebr/vendor/rails/activerecord/lib/active_record/migration.rb:383:in `migrate' 
/getweb/ebr/lib/tasks/data_fabric.rake:231:in `block (3 levels) in <top (required)>' 
/getweb/ebr/lib/tasks/data_fabric.rake:218:in `each' 
/getweb/ebr/lib/tasks/data_fabric.rake:218:in `block (2 levels) in <top (required)>' 
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:636:in `call' 
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:636:in `block in execute' 
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:631:in `each' 
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:631:in `execute' 
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:597:in `block in invoke_with_call_chain' 
/usr/local/lib/ruby/1.9.1/monitor.rb:190:in `mon_synchronize' 
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:590:in `invoke_with_call_chain' 
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:583:in `invoke' 
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:2051:in `invoke_task' 
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:2029:in `block (2 levels) in top_level' 
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:2029:in `each' 
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:2029:in `block in top_level' 
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling' 
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:2023:in `top_level' 
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:2001:in `block in run' 
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling' 
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:1998:in `run' 
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.8.7/bin/rake:31:in `<top (required)>' 
/usr/local/bin/rake:19:in `load' 
/usr/local/bin/rake:19:in `<main>'
Source
2010-06-04 Ollie Cooks