Cannot start rails server: Please install the adapter: `gem install activerecord--adapter`

My app was working sublime 'till this morning when I noticed this strange error when running rails server:

$ rails s
=> Booting WEBrick
=> Rails 3.2.1 application starting in development on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
Exiting
/usr/lib/ruby/gems/1.9.1/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:251:in require': Please install the adapter: gem install activerecord–adapter(cannot load such file -- active_record/connection_adapters/_adapter) (LoadError) from /usr/lib/ruby/gems/1.9.1/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:251:inblock in require’
from /usr/lib/ruby/gems/1.9.1/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:236:in load_dependency' from /usr/lib/ruby/gems/1.9.1/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:251:in require’
from /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.2.1/lib/active_record/connection_adapters/abstract/connection_specification.rb:48:in resolve_hash_connection' from /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.2.1/lib/active_record/connection_adapters/abstract/connection_specification.rb:39:in resolve_string_connection’
from /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.2.1/lib/active_record/connection_adapters/abstract/connection_specification.rb:23:in spec' from /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.2.1/lib/active_record/connection_adapters/abstract/connection_specification.rb:127:in establish_connection’
from /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.2.1/lib/active_record/railtie.rb:76:in block (2 levels) in <class:Railtie>' from /usr/lib/ruby/gems/1.9.1/gems/activesupport-3.2.1/lib/active_support/lazy_load_hooks.rb:36:in instance_eval’
from /usr/lib/ruby/gems/1.9.1/gems/activesupport-3.2.1/lib/active_support/lazy_load_hooks.rb:36:in execute_hook' from /usr/lib/ruby/gems/1.9.1/gems/activesupport-3.2.1/lib/active_support/lazy_load_hooks.rb:26:in on_load’
from /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.2.1/lib/active_record/railtie.rb:74:in block in <class:Railtie>' from /usr/lib/ruby/gems/1.9.1/gems/railties-3.2.1/lib/rails/initializable.rb:30:in instance_exec’
from /usr/lib/ruby/gems/1.9.1/gems/railties-3.2.1/lib/rails/initializable.rb:30:in run' from /usr/lib/ruby/gems/1.9.1/gems/railties-3.2.1/lib/rails/initializable.rb:55:in block in run_initializers’
from /usr/lib/ruby/gems/1.9.1/gems/railties-3.2.1/lib/rails/initializable.rb:54:in each' from /usr/lib/ruby/gems/1.9.1/gems/railties-3.2.1/lib/rails/initializable.rb:54:in run_initializers’
from /usr/lib/ruby/gems/1.9.1/gems/railties-3.2.1/lib/rails/application.rb:136:in initialize!' from /usr/lib/ruby/gems/1.9.1/gems/railties-3.2.1/lib/rails/railtie/configurable.rb:30:in method_missing’
from /home/al3xa/rails/sorcery/config/environment.rb:5:in <top (required)>' from /usr/lib/ruby/gems/1.9.1/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:251:in require’
from /usr/lib/ruby/gems/1.9.1/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:251:in block in require' from /usr/lib/ruby/gems/1.9.1/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:236:in load_dependency’
from /usr/lib/ruby/gems/1.9.1/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:251:in require' from /home/al3xa/rails/sorcery/config.ru:4:in block in ’
from /usr/lib/ruby/gems/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:51:in instance_eval' from /usr/lib/ruby/gems/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:51:in initialize’
from /home/al3xa/rails/sorcery/config.ru:1:in new' from /home/al3xa/rails/sorcery/config.ru:1:in
from /usr/lib/ruby/gems/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:40:in eval' from /usr/lib/ruby/gems/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:40:in parse_file’
from /usr/lib/ruby/gems/1.9.1/gems/rack-1.4.1/lib/rack/server.rb:200:in app' from /usr/lib/ruby/gems/1.9.1/gems/railties-3.2.1/lib/rails/commands/server.rb:46:in app’
from /usr/lib/ruby/gems/1.9.1/gems/rack-1.4.1/lib/rack/server.rb:301:in wrapped_app' from /usr/lib/ruby/gems/1.9.1/gems/rack-1.4.1/lib/rack/server.rb:252:in start’
from /usr/lib/ruby/gems/1.9.1/gems/railties-3.2.1/lib/rails/commands/server.rb:70:in start' from /usr/lib/ruby/gems/1.9.1/gems/railties-3.2.1/lib/rails/commands.rb:55:in block in <top (required)>’
from /usr/lib/ruby/gems/1.9.1/gems/railties-3.2.1/lib/rails/commands.rb:50:in tap' from /usr/lib/ruby/gems/1.9.1/gems/railties-3.2.1/lib/rails/commands.rb:50:in <top (required)>’
from script/rails:6:in require' from script/rails:6:in
Note that I can’t replicate this bug in vanilla apps. I’m using rubyRails 3.2.1 and ruby 1.9.3p0 (2011-10-30 revision 33570) [i686-linux]. FWIW, here’s my Gemfile too:

Getting the same error, did you ever get to the bottom of this?

Try to re-run bundle install and come back with results.

Did you run bundle update before ? As I see from your Gemfile, you did not specify gem versions, so may be you run in issue with some incompatible gems.

Check your database.yml file as well to be sure that you are still usin sqlite3 adapter, you should have something like this:

SQLite version 3.x

gem install sqlite3-ruby (not necessary on OS X Leopard)

development:

adapter: sqlite3

database: db/development.sqlite3

pool: 5

timeout: 5000