3 2008-08-26T15:57:00-04:00 Article summary tech_news 61 8 rake-db-migrate-fails-on-nil-info I'm posting this so that it can be Googled by others having the same/similar problem. <br/> <br/>In both Rails 1.2 and Rails 2.1 on Mac and Windows, I hit a problem in the ActiveRecord migration code which causes a database migration to abort. Here is the rake db:migrate --trace output: <br/> <br/><split/> <br/> <br/>[code]Macintosh:geekblog me$ rake db:migrate --trace <br/>(in /Users/me/rails/geekblog) <br/>** Invoke db:migrate (first_time) <br/>** Invoke environment (first_time) <br/>** Execute environment <br/>** has_many_polymorphs: rails environment detected <br/>** has_many_polymorphs: preloading parent model Tag <br/>** has_many_polymorphs: preloading parent model Tag <br/>** Execute db:migrate <br/>rake aborted! <br/>You have a nil object when you didn't expect it! <br/>[b]The error occurred while evaluating nil.info[/b] <br/>[b]/Library/Ruby/Gems/1.8/gems/activerecord-2.1.0/lib/active_record/migration.rb:421:in `migrate'[/b] <br/>/Library/Ruby/Gems/1.8/gems/activerecord-2.1.0/lib/active_record/migration.rb:420:in `each' <br/>/Library/Ruby/Gems/1.8/gems/activerecord-2.1.0/lib/active_record/migration.rb:420:in `migrate' <br/>/Library/Ruby/Gems/1.8/gems/activerecord-2.1.0/lib/active_record/migration.rb:357:in `up' <br/>/Library/Ruby/Gems/1.8/gems/activerecord-2.1.0/lib/active_record/migration.rb:340:in `migrate' <br/>/Library/Ruby/Gems/1.8/gems/rails-2.1.0/lib/tasks/databases.rake:99 <br/>/Library/Ruby/Gems/1.8/gems/rake-0.8.1/lib/rake.rb:546:in `call' <br/>/Library/Ruby/Gems/1.8/gems/rake-0.8.1/lib/rake.rb:546:in `execute' <br/>/Library/Ruby/Gems/1.8/gems/rake-0.8.1/lib/rake.rb:541:in `each' <br/>/Library/Ruby/Gems/1.8/gems/rake-0.8.1/lib/rake.rb:541:in `execute' <br/>/Library/Ruby/Gems/1.8/gems/rake-0.8.1/lib/rake.rb:508:in `invoke_with_call_chain' <br/>/Library/Ruby/Gems/1.8/gems/rake-0.8.1/lib/rake.rb:501:in `synchronize' <br/>/Library/Ruby/Gems/1.8/gems/rake-0.8.1/lib/rake.rb:501:in `invoke_with_call_chain' <br/>/Library/Ruby/Gems/1.8/gems/rake-0.8.1/lib/rake.rb:494:in `invoke' <br/>/Library/Ruby/Gems/1.8/gems/rake-0.8.1/lib/rake.rb:1931:in `invoke_task' <br/>/Library/Ruby/Gems/1.8/gems/rake-0.8.1/lib/rake.rb:1909:in `top_level' <br/>/Library/Ruby/Gems/1.8/gems/rake-0.8.1/lib/rake.rb:1909:in `each' <br/>/Library/Ruby/Gems/1.8/gems/rake-0.8.1/lib/rake.rb:1909:in `top_level' <br/>/Library/Ruby/Gems/1.8/gems/rake-0.8.1/lib/rake.rb:1948:in `standard_exception_handling' <br/>/Library/Ruby/Gems/1.8/gems/rake-0.8.1/lib/rake.rb:1903:in `top_level' <br/>/Library/Ruby/Gems/1.8/gems/rake-0.8.1/lib/rake.rb:1881:in `run' <br/>/Library/Ruby/Gems/1.8/gems/rake-0.8.1/lib/rake.rb:1948:in `standard_exception_handling' <br/>/Library/Ruby/Gems/1.8/gems/rake-0.8.1/lib/rake.rb:1878:in `run' <br/>/Library/Ruby/Gems/1.8/gems/rake-0.8.1/bin/rake:31 <br/>/usr/bin/rake:19:in `load' <br/>/usr/bin/rake:19 <br/>[/code] <br/> <br/>On line 421 of /Library/Ruby/Gems/1.8/gems/activerecord-2.1.0/lib/active_record/migration.rb, we find this: <br/> <br/>[code]Base.logger.info "Migrating to #{migration} (#{migration.version})"[/code] <br/> <br/>At this point, Base.logger is always null (nil) in all my Rails projects, at versions 1.2 and 2.1, on Mac and Windows, in development and production environments. I don't know why... But the fix is simple. Change the above line so that it checks to see if the logger is null (which it should probably be doing): <br/> <br/>[code]Base.logger.info "Migrating to #{migration} (#{migration.version})" unless Base.logger.nil?[/code] <br/> <br/>Since this "bug" has persisted for years, I assume this is a problem that others are not hitting. Logging works in my development and production environments, so logger should not be null in this case. <br/> <br/>*shrug* <br/> <br/>Life goes on. <br/> <br/>Anyone else hitting this problem with rake db:migrate? Let me know so we can bond and so on. 2008-09-12T00:37:48-04:00 1 2008