Rake DB:Create will not connect to PostGresql and set up database

Question

I've got a rails projects whose git repository I've forked and downloaded onto my computer. It's running for the other people on my team, however, when I run

rake db:create

I get the following error that it cannot connect to postgres, even though it's running on my computer.

could not connect to server: No such file or directory
    Is the server running locally and accepting
    connections on Unix domain socket "/var/pgsql_socket/.s.PGSQL.5432"?
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:888:in `initialize'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:888:in `new'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:888:in `connect'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:568:in `initialize'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:41:in `new'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:41:in `postgresql_connection'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:435:in `new_connection'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:445:in `checkout_new_connection'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:416:in `acquire_connection'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:351:in `block in checkout'
/usr/local/rvm/rubies/ruby-2.0.0-p481/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:350:in `checkout'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:265:in `block in connection'
/usr/local/rvm/rubies/ruby-2.0.0-p481/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:264:in `connection'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:541:in `retrieve_connection'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/connection_handling.rb:113:in `retrieve_connection'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/connection_handling.rb:87:in `connection'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/tasks/postgresql_database_tasks.rb:8:in `connection'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/tasks/postgresql_database_tasks.rb:17:in `create'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:88:in `create'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:102:in `block in create_current'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:209:in `block in each_current_configuration'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:208:in `each'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:208:in `each_current_configuration'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:101:in `create_current'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/activerecord-4.1.4/lib/active_record/railties/databases.rake:17:in `block (2 levels) in <top (required)>'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/rake-10.3.2/lib/rake/task.rb:240:in `call'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/rake-10.3.2/lib/rake/task.rb:240:in `block in execute'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/rake-10.3.2/lib/rake/task.rb:235:in `each'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/rake-10.3.2/lib/rake/task.rb:235:in `execute'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/rake-10.3.2/lib/rake/task.rb:179:in `block in invoke_with_call_chain'
/usr/local/rvm/rubies/ruby-2.0.0-p481/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/rake-10.3.2/lib/rake/task.rb:172:in `invoke_with_call_chain'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/rake-10.3.2/lib/rake/task.rb:165:in `invoke'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/rake-10.3.2/lib/rake/application.rb:150:in `invoke_task'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/rake-10.3.2/lib/rake/application.rb:106:in `block (2 levels) in top_level'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/rake-10.3.2/lib/rake/application.rb:106:in `each'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/rake-10.3.2/lib/rake/application.rb:106:in `block in top_level'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/rake-10.3.2/lib/rake/application.rb:115:in `run_with_threads'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/rake-10.3.2/lib/rake/application.rb:100:in `top_level'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/rake-10.3.2/lib/rake/application.rb:78:in `block in run'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/rake-10.3.2/lib/rake/application.rb:176:in `standard_exception_handling'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/rake-10.3.2/lib/rake/application.rb:75:in `run'
/usr/local/rvm/gems/ruby-2.0.0-p481/gems/rake-10.3.2/bin/rake:33:in `<top (required)>'
/usr/local/rvm/gems/ruby-2.0.0-p481/bin/rake:23:in `load'
/usr/local/rvm/gems/ruby-2.0.0-p481/bin/rake:23:in `<main>'
/usr/local/rvm/gems/ruby-2.0.0-p481/bin/ruby_executable_hooks:15:in `eval'
/usr/local/rvm/gems/ruby-2.0.0-p481/bin/ruby_executable_hooks:15:in `<main>'
Couldn't create database for {"adapter"=>"postgresql", "encoding"=>"unicode", "pool"=>5, "database"=>"source_development"}

Anyone have any ideas as to what could possibly be going on?

Answer 1

Your Pg gem is compiled against Apple's libpq not the libpq of the PostgreSQL you installed. So it has the wrong default unix_socket_directories.

Try:

host: /tmp

or

host: localhost