# Rake migrate error: nil.first **URL:** \ **Category:** Rails\ **Created:** [August 5, 2006, 6:00pm UTC](https://www.ruby-forum.com/t/rake-migrate-error-nil-first/101517 "2006-08-05T18:00:17Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![ldk2005](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/d9b06d/32.png) [@ldk2005](https://www.ruby-forum.com/u/ldk2005)\ **Post date:** [August 5, 2006, 6:00pm UTC](https://www.ruby-forum.com/t/rake-migrate-error-nil-first/101517/1 "2006-08-05T18:00:17Z")
My migrations were working fine until today. I dropped and re-created the database.But, when I go to apply my migrations, rake migrate aborts with this error. You have a nil object when you didn’t expect it! You might have expected an instance of Array. The error occured while evaluating nil.first Any idea what might be wrong? The migrations look right. It’s talking to the database ( I can see the new schema\_info table). I’m stumped on this one. ---
**Author:** ![ldk2005](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/d9b06d/32.png) [@ldk2005](https://www.ruby-forum.com/u/ldk2005)\ **Post date:** [August 5, 2006, 6:39pm UTC](https://www.ruby-forum.com/t/rake-migrate-error-nil-first/101517/2 "2006-08-05T18:39:20Z")
On Sat, 2006-08-05 at 08:55 -0700, Larry K. wrote: > this one. * * * add ‘–trace’ to the migrate command which should provide some meaningful information as to which line in your migration file is breaking/causing this Craig ---
**Author:** ![ldk2005](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/d9b06d/32.png) [@ldk2005](https://www.ruby-forum.com/u/ldk2005)\ **Post date:** [August 5, 2006, 6:45pm UTC](https://www.ruby-forum.com/t/rake-migrate-error-nil-first/101517/3 "2006-08-05T18:45:20Z")
Here is the trace output. But, I’m still not sure where I should be looking for the errors. -Larry \*\* Invoke migrate (first\_time) \*\* Invoke db:migrate (first\_time) \*\* Invoke environment (first\_time) \*\* Execute environment \*\* Execute db:migrate rake aborted! You have a nil object when you didn’t expect it! You might have expected an instance of Array. The error occured while evaluating nil.first /usr/lib/ruby/gems/1.8/gems/activerecord-1.14.3/lib/active\_record/migration.rb:3 57:in `migration_files' /usr/lib/ruby/gems/1.8/gems/activerecord-1.14.3/lib/active_record/connection_ada pters/mysql_adapter.rb:189:in`sort\_by’ /usr/lib/ruby/gems/1.8/gems/activerecord-1.14.3/lib/active\_record/migration.rb:3 56:in `migration_files' /usr/lib/ruby/gems/1.8/gems/activerecord-1.14.3/lib/active_record/migration.rb:3 39:in`migration\_classes’ /usr/lib/ruby/gems/1.8/gems/activerecord-1.14.3/lib/active\_record/migration.rb:3 27:in `migrate' /usr/lib/ruby/gems/1.8/gems/activerecord-1.14.3/lib/active_record/migration.rb:2 94:in`up’ /usr/lib/ruby/gems/1.8/gems/activerecord-1.14.3/lib/active\_record/migration.rb:2 85:in `migrate' /usr/lib/ruby/gems/1.8/gems/rails-1.1.4/lib/tasks/databases.rake:4 /usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:387:in`execute’ /usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:387:in `execute' /usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:357:in`invoke’ /usr/lib/ruby/1.8/thread.rb:135:in `synchronize' /usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:350:in`invoke’ /usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:364:in `invoke_prerequisites' /usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:999:in`each’ /usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:363:in `invoke_prerequisites' /usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:356:in`invoke’ /usr/lib/ruby/1.8/thread.rb:135:in `synchronize' /usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:350:in`invoke’ /usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:1906:in `run' /usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:1906:in`run’ /usr/lib/ruby/gems/1.8/gems/rake-0.7.1/bin/rake:7 /usr/bin/rake:18 ---
**Author:** ![ldk2005](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/d9b06d/32.png) [@ldk2005](https://www.ruby-forum.com/u/ldk2005)\ **Post date:** [August 6, 2006, 3:22am UTC](https://www.ruby-forum.com/t/rake-migrate-error-nil-first/101517/4 "2006-08-06T03:22:12Z")
Thanks Damon, I moved all the migrations out, re-created the db, and applied the migrations one by one. In the process, I discovered that some old svn changes had gotten mixed in with my migrations. Once, I cleared that up. the migrations ran as expected. -Larry ---
**Author:** ![ldk2005](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/d9b06d/32.png) [@ldk2005](https://www.ruby-forum.com/u/ldk2005)\ **Post date:** [August 5, 2006, 9:09pm UTC](https://www.ruby-forum.com/t/rake-migrate-error-nil-first/101517/5 "2006-08-05T21:09:29Z")
Larry K. \ writes: > Here is the trace output. But, I’m still not sure where I should be looking > for the errors. -Larry\*\* Invoke migrate (first\_time)\*\* Invoke db:migrate > (first\_time)\*\* Invoke environment (first\_time)\*\* Execute environment > \*\* Execute db:migraterake aborted!You have a nil object when you didn’t expect > it!You might have expected an instance of Array.The error occured while > evaluating nil.first/usr/lib/ruby/gems/1.8/gems/activerecord- > 1.14.3/lib/active\_record/migration.rb:3 57:in `migration\_files’ Here are the relevant lines from migration.rb: 355 def migration\_files 356 files = Dir[“#{@migrations\_path}/[0-9]_\__.rb”].sort\_by do |f| 357 migration\_version\_and\_name(f).first.to\_i 358 end 359 down? ? files.reverse : files 360 end 361 362 def migration\_class(migration\_name) 363 migration\_name.camelize.constantize 364 end 365 366 def migration\_version\_and\_name(migration\_file) 367 return _migration\_file.scan(/([0-9]+)\_([\_a-z0-9]_).rb/).first 368 end Line 357 is the problem line. So somehow when it is scanning your /db/migrate directory for relevant files, there is something in there that is not in the typical form of migration naming 001\_my\_migration.rb. Try clearing out any non-migration files from db/migrate and try again. Good luck, -damon > **[Damon Clinkscales](https://damonc.onuniverse.com/)** > > Damon Clinkscales ---
**Author:** ![ldk2005](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/d9b06d/32.png) [@ldk2005](https://www.ruby-forum.com/u/ldk2005)\ **Post date:** [August 6, 2006, 3:50am UTC](https://www.ruby-forum.com/t/rake-migrate-error-nil-first/101517/6 "2006-08-06T03:50:28Z")
Larry K. wrote: > Thanks Damon, > > I moved all the migrations out, re-created the db, and applied the > migrations one by one. In the process, I discovered that some old svn > changes had gotten mixed in with my migrations. Once, I cleared that > up. > the migrations ran as expected. > -Larry Most excellent. -damon > **[Damon Clinkscales](https://damonc.onuniverse.com/)** > > Damon Clinkscales