我的同事和我正在使用Rails 4.1.8。我们正在研究裸机（没有Docker，没有VM）。我的cowerker使用的是Ruby 2.0.0，而我使用的是2.1.5。我们同意转向同一版本。
我的同事开始研究这个问题而没有把它放到Github上。他用scp将它放在亚马逊的服务器上。我的同事安装了RefineryCMS的视频插件，可以运行：
rake db:seed
我不知道他是在使用bundle exec还是依赖系统宝石。
我使用scp从亚马逊下载代码。我得到了.gitignore通常会保留的所有文件。我安装了会员插件，如果我运行命令：
bundle exec rake db:seed
我收到错误：
ActiveRecord::RecordInvalid: Validation failed: Title can't be blank, Parts title can't be blank
并且堆栈跟踪指向：
/Users/cerhovice/projects/patton/royalbeauty/vendor/extensions/videos/db/seeds.rb:10:in `block in <top (required)>'
完整的回溯看起来像这样：
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activerecord-4.1.8/lib/active_record/validations.rb:57:in `save!'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activerecord-4.1.8/lib/active_record/attribute_methods/dirty.rb:29:in `save!'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activerecord-4.1.8/lib/active_record/transactions.rb:273:in `block in save!'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activerecord-4.1.8/lib/active_record/transactions.rb:329:in `block in with_transaction_returning_status'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activerecord-4.1.8/lib/active_record/connection_adapters/abstract/database_statements.rb:201:in `block in transaction'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activerecord-4.1.8/lib/active_record/connection_adapters/abstract/database_statements.rb:209:in `within_new_transaction'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activerecord-4.1.8/lib/active_record/connection_adapters/abstract/database_statements.rb:201:in `transaction'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activerecord-4.1.8/lib/active_record/transactions.rb:208:in `transaction'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activerecord-4.1.8/lib/active_record/transactions.rb:326:in `with_transaction_returning_status'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activerecord-4.1.8/lib/active_record/transactions.rb:273:in `save!'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/protected_attributes-1.0.8/lib/active_record/mass_assignment_security/validations.rb:17:in `create!'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activerecord-4.1.8/lib/active_record/relation.rb:147:in `block in create!'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activerecord-4.1.8/lib/active_record/relation.rb:292:in `scoping'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activerecord-4.1.8/lib/active_record/relation.rb:147:in `create!'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activerecord-4.1.8/lib/active_record/relation.rb:155:in `first_or_create!'
/Users/cerhovice/projects/patton/royalbeauty/vendor/extensions/videos/db/seeds.rb:10:in `block in <top (required)>'
/Users/cerhovice/projects/patton/royalbeauty/vendor/extensions/videos/db/seeds.rb:1:in `each'
/Users/cerhovice/projects/patton/royalbeauty/vendor/extensions/videos/db/seeds.rb:1:in `<top (required)>'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activesupport-4.1.8/lib/active_support/dependencies.rb:241:in `load'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activesupport-4.1.8/lib/active_support/dependencies.rb:241:in `block in load'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activesupport-4.1.8/lib/active_support/dependencies.rb:232:in `load_dependency'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activesupport-4.1.8/lib/active_support/dependencies.rb:241:in `load'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/railties-4.1.8/lib/rails/engine.rb:543:in `load_seed'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/railties-4.1.8/lib/rails/railtie.rb:194:in `public_send'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/railties-4.1.8/lib/rails/railtie.rb:194:in `method_missing'
/Users/cerhovice/projects/patton/royalbeauty/db/seeds.rb:13:in `<top (required)>'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activesupport-4.1.8/lib/active_support/dependencies.rb:241:in `load'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activesupport-4.1.8/lib/active_support/dependencies.rb:241:in `block in load'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activesupport-4.1.8/lib/active_support/dependencies.rb:232:in `load_dependency'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activesupport-4.1.8/lib/active_support/dependencies.rb:241:in `load'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/railties-4.1.8/lib/rails/engine.rb:543:in `load_seed'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activerecord-4.1.8/lib/active_record/tasks/database_tasks.rb:200:in `load_seed'
/Users/cerhovice/projects/patton/royalbeauty/vendor/bundle/ruby/2.1.0/gems/activerecord-4.1.8/lib/active_record/railties/databases.rake:174:in `block (2 levels) in <top (required)>'
Tasks: TOP => db:seed
我打开了该文件，并检查了part和index的值：
Refinery::Page.where(link_url: (url = "/videos")).first_or_create!(
title: 'Videos',
deletable: false,
menu_match: "^#{url}(\/|\/.+?|)$"
) do |page|
Refinery::Pages.default_parts.each_with_index do |part, index|
[part, index] # => [Body, 0], then [Side Body, 1]
page.parts.build title: part, body: nil, position: index
end
end if defined?(Refinery::Page)
尽管堆栈跟踪说的是，如果在我刚刚安装的插件中发生此错误会更有意义，所以我打开了：
vendor/bundle/ruby/2.1.0/bundler/gems/refinerycms_membership-cd49cac06a43/db/seeds.rb
我添加了一些put语句。这些从未在终端中显示。相反，我得到上面的输出，然后是rake aborted!。
它适用于我的同事，但不适合我。 Rails程序员通常会如何调试这种问题？我该如何开始调试呢？我不是要求RefineryCMS提供帮助。
来自log / development.log：
(0.1ms) SELECT MAX("refinery_user_plugins"."position") AS max_id FROM "refinery_user_plugins" WHERE "refinery_user_plugins"."user_id" = ? [["user_id", 4]]
Refinery::UserPlugin Load (0.1ms) SELECT "refinery_user_plugins".* FROM "refinery_user_plugins" WHERE "refinery_user_plugins"."user_id" = ? AND "refinery_user_plugins"."name" = 'refinerycms-videos' ORDER BY position ASC LIMIT 1 [["user_id", 4]]
Refinery::Page Load (0.2ms) SELECT "refinery_pages".* FROM "refinery_pages" WHERE "refinery_pages"."link_url" = '/videos' ORDER BY "refinery_pages"."id" ASC LIMIT 1
WARNING: Can't mass-assign protected attributes for Refinery::Page: title, deletable, menu_match
WARNING: Can't mass-assign protected attributes for Refinery::PagePart: title, body, position
WARNING: Can't mass-assign protected attributes for Refinery::PagePart: title, body, position
(0.1ms) begin transaction
Refinery::PagePart Exists (0.2ms) SELECT 1 AS one FROM "refinery_page_parts" WHERE ("refinery_page_parts"."title" IS NULL AND "refinery_page_parts"."refinery_page_id" IS NULL) LIMIT 1
Refinery::PagePart Exists (0.1ms) SELECT 1 AS one FROM "refinery_page_parts" WHERE ("refinery_page_parts"."title" IS NULL AND "refinery_page_parts"."refinery_page_id" IS NULL) LIMIT 1
(0.1ms) rollback transaction