自己在做一个 demo 来学习 ror，之前部署在 heroku 一直好好的，然后昨天学习了 carrierwave 的使用。在本地一切都 ok，但 push 到 heroku 之后，打开 demo 地址，发现无法加载，使用heroku logs, 报错：

/app/app/models/article.rb: 9: in `class:Article': uninitialized constant Article::PictureUploader (NameError).

之后发现无论是heroku run rails s还是heroku run rails c都是报这个错误。我不太明白，为和本地可以良好运行而远程就不行？故求助。

app/uploaders/picture_uploader.rb

class PictureUploader < CarrierWave::Uploader::Base
  include CarrierWave::MiniMagick
  process resize_to_limit: [600, 600]
  storage :qiniu

  def store_dir
    "uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
  end

  def extension_white_list
    %w{jpg gif png jpeg}
  end
end

app/models/article.rb

class Article < ActiveRecord::Base
  belongs_to :user
  has_many :comments, dependent: :destroy
  has_many :likes
  validates :title, presence: true, length: {maximum: 50}
  validates :content, length: {minimum: 10}
  self.per_page = 10
  attr_accessor :floor_number
  mount_uploader :picture, PictureUploader
  validate :picture_size

  def picture_size
    if picture.size > 5.megabytes
        errors.add(:picture, "should be less than 5MB")
    end
  end
end

github: https://github.com/killernova/blog