我运行rake db:migrate，迁移工作正常。但是，当我尝试使用任何rake命令时，它会给我这个错误。
/Library/Ruby/Gems/2.0.0/gems/devise-3.5.6/lib/devise/models.rb:80:in `map': undefined method `to_sym' for nil:NilClass (NoMethodError)
我不确定如何解决此问题，因为rake db:rollback也会导致错误。
修改
devise :database_authenticatable, :registerable,
:recoverable, :rememberable, :trackable, :validatable,
来自用户
这是整个错误
from /Library/Ruby/Gems/2.0.0/gems/devise-3.5.6/lib/devise/models.rb:80:in `devise'
from /Users/Noah/Desktop/Wellness/welness/app/models/user.rb:4:in `<class:User>'
from /Users/Noah/Desktop/Wellness/welness/app/models/user.rb:1:in `<top (required)>'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:457:in `load'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:457:in `block in load_file'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:647:in `new_constants_in'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:456:in `load_file'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:354:in `require_or_load'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:494:in `load_missing_constant'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:184:in `const_missing'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/inflector/methods.rb:261:in `const_get'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/inflector/methods.rb:261:in `block in constantize'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/inflector/methods.rb:259:in `each'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/inflector/methods.rb:259:in `inject'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/inflector/methods.rb:259:in `constantize'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:566:in `get'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:597:in `constantize'
from /Library/Ruby/Gems/2.0.0/gems/devise-3.5.6/lib/devise.rb:292:in `get'
from /Library/Ruby/Gems/2.0.0/gems/devise-3.5.6/lib/devise/mapping.rb:81:in `to'
from /Library/Ruby/Gems/2.0.0/gems/devise-3.5.6/lib/devise/mapping.rb:76:in `modules'
from /Library/Ruby/Gems/2.0.0/gems/devise-3.5.6/lib/devise/mapping.rb:93:in `routes'
from /Library/Ruby/Gems/2.0.0/gems/devise-3.5.6/lib/devise/mapping.rb:160:in `default_used_route'
from /Library/Ruby/Gems/2.0.0/gems/devise-3.5.6/lib/devise/mapping.rb:70:in `initialize'
from /Library/Ruby/Gems/2.0.0/gems/devise-3.5.6/lib/devise.rb:326:in `new'
from /Library/Ruby/Gems/2.0.0/gems/devise-3.5.6/lib/devise.rb:326:in `add_mapping'
from /Library/Ruby/Gems/2.0.0/gems/devise-3.5.6/lib/devise/rails/routes.rb:238:in `block in devise_for'
from /Library/Ruby/Gems/2.0.0/gems/devise-3.5.6/lib/devise/rails/routes.rb:237:in `each'
from /Library/Ruby/Gems/2.0.0/gems/devise-3.5.6/lib/devise/rails/routes.rb:237:in `devise_for'
from /Users/Noah/Desktop/Wellness/welness/config/routes.rb:7:in `block in <top (required)>'
from /Library/Ruby/Gems/2.0.0/gems/actionpack-4.2.5/lib/action_dispatch/routing/route_set.rb:434:in `instance_exec'
from /Library/Ruby/Gems/2.0.0/gems/actionpack-4.2.5/lib/action_dispatch/routing/route_set.rb:434:in `eval_block'
from /Library/Ruby/Gems/2.0.0/gems/actionpack-4.2.5/lib/action_dispatch/routing/route_set.rb:412:in `draw'
from /Users/Noah/Desktop/Wellness/welness/config/routes.rb:1:in `<top (required)>'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:268:in `load'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:268:in `block in load'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:240:in `load_dependency'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:268:in `load'
from /Library/Ruby/Gems/2.0.0/gems/railties-4.2.5/lib/rails/application/routes_reloader.rb:40:in `block in load_paths'
from /Library/Ruby/Gems/2.0.0/gems/railties-4.2.5/lib/rails/application/routes_reloader.rb:40:in `each'
from /Library/Ruby/Gems/2.0.0/gems/railties-4.2.5/lib/rails/application/routes_reloader.rb:40:in `load_paths'
from /Library/Ruby/Gems/2.0.0/gems/railties-4.2.5/lib/rails/application/routes_reloader.rb:16:in `reload!'
from /Library/Ruby/Gems/2.0.0/gems/railties-4.2.5/lib/rails/application/routes_reloader.rb:26:in `block in updater'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/file_update_checker.rb:75:in `call'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/file_update_checker.rb:75:in `execute'
from /Library/Ruby/Gems/2.0.0/gems/railties-4.2.5/lib/rails/application/routes_reloader.rb:27:in `updater'
from /Library/Ruby/Gems/2.0.0/gems/railties-4.2.5/lib/rails/application/routes_reloader.rb:7:in `execute_if_updated'
from /Library/Ruby/Gems/2.0.0/gems/railties-4.2.5/lib/rails/application/finisher.rb:69:in `block in <module:Finisher>'
from /Library/Ruby/Gems/2.0.0/gems/railties-4.2.5/lib/rails/initializable.rb:30:in `instance_exec'
from /Library/Ruby/Gems/2.0.0/gems/railties-4.2.5/lib/rails/initializable.rb:30:in `run'
from /Library/Ruby/Gems/2.0.0/gems/railties-4.2.5/lib/rails/initializable.rb:55:in `block in run_initializers'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/tsort.rb:150:in `block in tsort_each'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/tsort.rb:183:in `block (2 levels) in each_strongly_connected_component'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/tsort.rb:219:in `each_strongly_connected_component_from'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/tsort.rb:182:in `block in each_strongly_connected_component'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/tsort.rb:180:in `each'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/tsort.rb:180:in `each_strongly_connected_component'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/tsort.rb:148:in `tsort_each'
from /Library/Ruby/Gems/2.0.0/gems/railties-4.2.5/lib/rails/initializable.rb:54:in `run_initializers'
from /Library/Ruby/Gems/2.0.0/gems/railties-4.2.5/lib/rails/application.rb:352:in `initialize!'
from /Users/Noah/Desktop/Wellness/welness/config/environment.rb:5:in `<top (required)>'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `require'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `block in require'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:240:in `load_dependency'
from /Library/Ruby/Gems/2.0.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `require'
from /Users/Noah/Desktop/Wellness/welness/config.ru:3:in `block in <main>'
from /Library/Ruby/Gems/2.0.0/gems/rack-1.6.4/lib/rack/builder.rb:55:in `instance_eval'
from /Library/Ruby/Gems/2.0.0/gems/rack-1.6.4/lib/rack/builder.rb:55:in `initialize'
from /Users/Noah/Desktop/Wellness/welness/config.ru:in `new'
from /Users/Noah/Desktop/Wellness/welness/config.ru:in `<main>'
from /Library/Ruby/Gems/2.0.0/gems/rack-1.6.4/lib/rack/builder.rb:49:in `eval'
from /Library/Ruby/Gems/2.0.0/gems/rack-1.6.4/lib/rack/builder.rb:49:in `new_from_string'
from /Library/Ruby/Gems/2.0.0/gems/rack-1.6.4/lib/rack/builder.rb:40:in `parse_file'
from /Library/Ruby/Gems/2.0.0/gems/rack-1.6.4/lib/rack/server.rb:299:in `build_app_and_options_from_config'
from /Library/Ruby/Gems/2.0.0/gems/rack-1.6.4/lib/rack/server.rb:208:in `app'
from /Library/Ruby/Gems/2.0.0/gems/railties-4.2.5/lib/rails/commands/server.rb:61:in `app'
from /Library/Ruby/Gems/2.0.0/gems/rack-1.6.4/lib/rack/server.rb:336:in `wrapped_app'
from /Library/Ruby/Gems/2.0.0/gems/railties-4.2.5/lib/rails/commands/server.rb:139:in `log_to_stdout'
from /Library/Ruby/Gems/2.0.0/gems/railties-4.2.5/lib/rails/commands/server.rb:78:in `start'
from /Library/Ruby/Gems/2.0.0/gems/railties-4.2.5/lib/rails/commands/commands_tasks.rb:80:in `block in server'
from /Library/Ruby/Gems/2.0.0/gems/railties-4.2.5/lib/rails/commands/commands_tasks.rb:75:in `tap'
from /Library/Ruby/Gems/2.0.0/gems/railties-4.2.5/lib/rails/commands/commands_tasks.rb:75:in `server'
from /Library/Ruby/Gems/2.0.0/gems/railties-4.2.5/lib/rails/commands/commands_tasks.rb:39:in `run_command!'
from /Library/Ruby/Gems/2.0.0/gems/railties-4.2.5/lib/rails/commands.rb:17:in `<top (required)>'
from /Users/Noah/Desktop/Wellness/welness/bin/rails:9:in `require'
from /Users/Noah/Desktop/Wellness/welness/bin/rails:9:in `<top (required)>'
from /Library/Ruby/Gems/2.0.0/gems/spring-1.6.4/lib/spring/client/rails.rb:28:in `load'
from /Library/Ruby/Gems/2.0.0/gems/spring-1.6.4/lib/spring/client/rails.rb:28:in `call'
from /Library/Ruby/Gems/2.0.0/gems/spring-1.6.4/lib/spring/client/command.rb:7:in `call'
from /Library/Ruby/Gems/2.0.0/gems/spring-1.6.4/lib/spring/client.rb:28:in `run'
from /Library/Ruby/Gems/2.0.0/gems/spring-1.6.4/bin/spring:49:in `<top (required)>'
from /Library/Ruby/Gems/2.0.0/gems/spring-1.6.4/lib/spring/binstub.rb:11:in `load'
from /Library/Ruby/Gems/2.0.0/gems/spring-1.6.4/lib/spring/binstub.rb:11:in `<top (required)>'
from /Library/Ruby/Site/2.0.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from /Library/Ruby/Site/2.0.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from /Users/Noah/Desktop/Wellness/welness/bin/spring:13:in `<top (required)>'
from bin/rails:3:in `load'
from bin/rails:3:in `<main>'
它的rake v 11.1.2