Ruby on rails “奇怪”；ArgumentError:密钥不能为空"；关于aws S3

我有一个rails应用程序，允许用户直接上传与帖子相关的图像到S3，然后运行图像处理“延迟”作业来调整大小。使用web浏览器时，一切正常，但最近我编写了一些数据库填充任务，但当我尝试保存图像及其相关模型时，此错误显示：

ArgumentError:key可能不是空的

。任何关于为什么会发生这种情况的想法都很好

populate.rake代码的片段：

post = Post.new(user: user)
((rand*5).floor + 1).times do

      ## Here, you will need to upload the file to S3, get the direct_upload_url then save it for img.direct_upload_url
      # Upload to S3, then get the direct_upload_url
      file=File.open(Dir.glob(File.join(Rails.root, 'sampleimages/posts', '*')).sample)
      s3_obj = S3_BUCKET.objects["direct_uploads/#{Time.now.to_i}/#{File.basename(file)}"]
      puts "    Selected file: #{File.basename(file)}"
      puts "      --> Starting upload"

      s3_obj.write(file)
      #s3_obj.acl= :public_read
      obj_url = ""

      while obj_url.blank?
        obj_url = s3_obj.url_for(:read)
        sleep(3)
      end
      puts "    --> Loop completed with obj_url = #{obj_url}"
      img = post.images.build(direct_upload_url: obj_url.to_s)

      # puts "url_for #{obj_url}"

      puts "Image uploaded: #{s3_obj.key} URL: #{img.direct_upload_url}\n"
      # The below code is used for local file storage
      #img.image_file = File.open(Dir.glob(File.join(Rails.root, 'sampleimages/posts', '*')).sample)
    end

    post.save!

end

错误出现在

post.save

下面是
Image.rb
：

## S3_direct_upload post processing!
before_create :set_upload_attributes
### setting the image_to_process of this image.
before_create :inc_images_to_process
after_create :queue_processing

def direct_upload_url=(escaped_url)
  write_attribute(:direct_upload_url, (CGI.unescape(escaped_url) rescue nil))
end

# Determines if file requires post-processing (image resizing, etc)
# All files should be processable in my case, where only images can be stored.
def post_process_required?
  %r{^(image|(x-)?application)/(bmp|gif|jpeg|jpg|pjpeg|png|x-png)$}.match(image_file_content_type).present?
end



# Final upload processing step
def self.transfer_and_cleanup(id)
  begin
    ## This will raise exception, need to catch this.
    image = Image.find_by_id(id)
    ## Check if the image still exists when this is running, if not, then just skip this and minus one from post
    if image.nil? || image.processed
      ## Something's wrong, either the image is not present or the image is already processed
      Delayed::Worker.logger.debug "ERROR: Image with id: #{id} Not Found. This file will still up on aws temp!"
      ## The file is not here anymore.
      ## Ask the post to recalculate how many images it actually has!
        if image.present? && image.processed 
          direct_upload_url_data = DIRECT_UPLOAD_URL_FORMAT.match(image.direct_upload_url)
          S3_BUCKET.objects[direct_upload_url_data[:path]].delete
        end
    else
        ## With this match, path and filename will be extracted.
        direct_upload_url_data = DIRECT_UPLOAD_URL_FORMAT.match(image.direct_upload_url)

        if image.post_process_required?
          image.image_file = URI.parse(URI.escape(image.direct_upload_url))
        else
            # Somethings's wrong???!?!?!? It should be images!
          paperclip_file_path = "images/uploads/#{id}/original/#{direct_upload_url_data[:filename]}"
          S3_BUCKET.objects[paperclip_file_path].copy_from(direct_upload_url_data[:path])
      end

      image.processed = true

      if image.save
          ## To unset the image_to_process field of its parent - the Post
          if image.imageable.class.to_s == "Post"
            # logger.debug "I am here!!!"
            post = image.imageable
            post.images_to_process -= 1
            post.save!
          end
          Delayed::Worker.logger.debug "Image:#{id}:transfer_and_cleanup: It is now saved"

      else
          Delayed::Worker.logger.debug "Image:#{id}:transfer_and_cleanup: ERROR Occurs: #{image.errors.full_messages}"
      end
      ### End of image.save

      ## Delete the temp file.
      Delayed::Worker.logger.debug "Image:#{id}:transfer_and_cleanup: direct_upload_url: #{direct_upload_url} is going to deleted"
      S3_BUCKET.objects[direct_upload_url_data[:path]].delete

    end
    ## end of image.present? loop
  end




end ## End of transfer_and_cleanup



  # Set attachment attributes from the direct upload
  # @note Retry logic handles S3 "eventual consistency" lag.
  def set_upload_attributes
    logger.debug "You are now in set_upload_attributes"
    tries ||= 5
    direct_upload_url_data = DIRECT_UPLOAD_URL_FORMAT.match(direct_upload_url)

    direct_upload_head = S3_BUCKET.objects[direct_upload_url_data[:path]].head

    self.image_file_file_name     = direct_upload_url_data[:filename]
    self.image_file_file_size     = direct_upload_head.content_length
    self.image_file_content_type  = direct_upload_head.content_type
    self.image_file_updated_at    = direct_upload_head.last_modified


    ## Rescue the S3 Errors here

    rescue AWS::S3::Errors::NoSuchKey => e
      tries -= 1
      if tries > 0
        sleep(3)
        retry
      else
        false
      end
  end

  # Queue file processing
  def queue_processing
    Image.delay.transfer_and_cleanup(id)
    Delayed::Worker.logger.debug "queue_processing: Image #{id} added in the queue. At "
  end

  def inc_images_to_process
    # Increase the image required to process in Post.
    if self.imageable.class.to_s == "Post"

      post = self.imageable
      post.inc_images_to_process

      Delayed::Worker.logger.debug "inc_images_to_process: Post #{post.id} new images_to_process is now: #{post.images_to_process}"
    end
  end

错误消息如下：

rake aborted!
ArgumentError: key may not be blank
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/s3/client.rb:384:in `validate!'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/s3/client.rb:390:in `validate_key!'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/s3/client.rb:542:in `block (2 levels) in object_method'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/s3/client.rb:1563:in `block (2 levels) in <class:V20060301>'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/client.rb:560:in `build_request'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/client.rb:491:in `block (3 levels) in client_request'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/response.rb:175:in `call'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/response.rb:175:in `build_request'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/response.rb:114:in `initialize'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/client.rb:203:in `new'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/client.rb:203:in `new_response'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/client.rb:490:in `block (2 levels) in client_request'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/client.rb:391:in `log_client_request'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/client.rb:477:in `block in client_request'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/client.rb:373:in `return_or_raise'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/client.rb:476:in `client_request'
(eval):3:in `head_object'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/s3/s3_object.rb:296:in `head'
/Users/quindici/Documents/Career/QUIN CREATIVES/Local-say/Local-say-System/app/models/image.rb:134:in `set_upload_attributes'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/callbacks.rb:377:in `_run__4088547230130556858__create__callbacks'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/callbacks.rb:80:in `run_callbacks'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/callbacks.rb:303:in `create_record'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/timestamp.rb:57:in `create_record'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/persistence.rb:466:in `create_or_update'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/callbacks.rb:299:in `block in create_or_update'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/callbacks.rb:383:in `_run__4088547230130556858__save__callbacks'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/callbacks.rb:80:in `run_callbacks'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/callbacks.rb:299:in `create_or_update'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/persistence.rb:106:in `save'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/validations.rb:51:in `save'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/attribute_methods/dirty.rb:32:in `save'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/transactions.rb:270:in `block (2 levels) in save'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/transactions.rb:326:in `block in with_transaction_returning_status'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/database_statements.rb:200:in `transaction'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/transactions.rb:209:in `transaction'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/transactions.rb:323:in `with_transaction_returning_status'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/transactions.rb:270:in `block in save'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/transactions.rb:281:in `rollback_active_record_state!'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/transactions.rb:269:in `save'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/associations/has_many_association.rb:39:in `insert_record'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/autosave_association.rb:348:in `block in save_collection_association'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/autosave_association.rb:339:in `each'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/autosave_association.rb:339:in `save_collection_association'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/autosave_association.rb:183:in `block in add_autosave_association_callbacks'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/autosave_association.rb:153:in `instance_eval'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/autosave_association.rb:153:in `block in define_non_cyclic_method'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/callbacks.rb:383:in `_run__690630312330398441__update__callbacks'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/callbacks.rb:80:in `run_callbacks'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/callbacks.rb:307:in `update_record'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/timestamp.rb:70:in `update_record'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/persistence.rb:466:in `create_or_update'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/callbacks.rb:299:in `block in create_or_update'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/callbacks.rb:413:in `_run__690630312330398441__save__callbacks'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/callbacks.rb:80:in `run_callbacks'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/callbacks.rb:299:in `create_or_update'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/persistence.rb:128:in `save!'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/validations.rb:57:in `save!'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/attribute_methods/dirty.rb:41:in `save!'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/transactions.rb:275:in `block in save!'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/transactions.rb:326:in `block in with_transaction_returning_status'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/database_statements.rb:202:in `block in transaction'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/database_statements.rb:210:in `within_new_transaction'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/database_statements.rb:202:in `transaction'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/transactions.rb:209:in `transaction'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/transactions.rb:323:in `with_transaction_returning_status'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/transactions.rb:275:in `save!'
/Users/quindici/Documents/Career-System/lib/tasks/populate.rake:139:in `block (4 levels) in <top (required)>'
/Users/quindici/Documents/Career-System/lib/tasks/populate.rake:56:in `times'
/Users/quindici/Documents/Career-System/lib/tasks/populate.rake:56:in `block (3 levels) in <top (required)>'
/Users/quindici/Documents/Career-System/lib/tasks/populate.rake:31:in `times'
/Users/quindici/Documents/Career-System/lib/tasks/populate.rake:31:in `block (2 levels) in <top (required)>'
Tasks: TOP => db:db_populate

rake中止！
ArgumentError:密钥不能为空
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/s3/client.rb:384:in'validate！'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/s3/client.rb:390:in'validate_key！'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/s3/client.rb:542:in`block（2层）in object_方法'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/s3/client.rb:1563:in'block（2层）in'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/client.rb:560:在“构建请求”中
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/client.rb:491:在“客户端请求中的块（3个级别）”中
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/response.rb:175:in'call'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/response.rb:175:在“构建请求”中
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/response.rb:114:in'initialize'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/client.rb:203:in'new'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/client.rb:203:in“new_response”
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/client.rb:490:in `客户端请求中的块（2级）'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/client.rb:391:in'log\u client\u request'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/client.rb:477:在“客户端请求中的块”中
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/client.rb:373:in'return_或_raise'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/core/client.rb:476:in'client_request'
（eval）：3:在“head_object”中
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/aws-sdk-v1-1.56.0/lib/aws/s3/s3_object.rb:296:in'head'
/Users/quindici/Documents/Career/QUIN CREATIVES/Local say/Local say System/app/models/image.rb:134:在“设置上传属性”中
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active\u-support/callbacks.rb:377:在“运行”中
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active\u support/callbacks.rb:80:in'run\u callbacks'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active\u record/callbacks.rb:303:in'create\u record'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active\u record/timestamp.rb:57:in'create\u record'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active\u record/persistence.rb:466:在“创建或更新”中
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active\u record/callbacks.rb:299:in'block in create\u或\u update'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active\u-support/callbacks.rb:383:在“运行”中
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active\u support/callbacks.rb:80:in'run\u callbacks'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active\u record/callbacks.rb:299:in'create\u或\u update'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active\u record/persistence.rb:106:in'save'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active\u record/validations.rb:51:in'save'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active\u record/attribute\u methods/dirty.rb:32:在“保存”中
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/transactions.rb:270:在“保存中的块（2个级别）”中
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active\u record/transactions.rb:326:in`block in with\u transaction\u returning\u status'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active\u record/connection\u adapters/abstract/database\u语句。rb:200:in'transaction'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/transactions.rb:209:in'transaction'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active\u record/transactions.rb:323:in`with\u transaction\u returning\u status'
/Users/quindici/.rvm/gems/ruby-2.0.0-p247@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active\u record/transactions.rb:270：