ruby - 为 nil 调用私有方法“split”：NilClass

Question

我正在使用 sitemap_generator ( https://github.com/kjvarga/sitemap_generator ) gem 并且似乎我的代码在开发环境中运行良好，但是当我尝试在生产环境中运行它时出现以下错误：

private method `split' called for nil:NilClass

这只发生在生产环境中（在我的机器和生产服务器上），一切都在开发中运行良好。这是我的站点地图代码，它位于 config/sitemap.rb 中：

SitemapGenerator::Sitemap.default_host = "https://www.mysite.com"
SitemapGenerator::Sitemap.create do
  # The root path '/' and sitemap index file are added automatically for you.
  # Links are added to the Sitemap in the order they are specified.  

  add '/classifieds', :changefreq => 'yearly', :priority => 0.75, :lastmod => '2013-01-01'
  add '/sell_modified_cars', :changefreq => 'yearly', :priority => 0.75, :lastmod => '2013-01-01'
  add '/sell_race_cars', :changefreq => 'yearly', :priority => 0.75, :lastmod => '2013-01-01'

  add '/motorsport_event/organizations', :changefreq => 'monthly', :priority => 0.8, :lastmod => Organization.last.created_at

  Organization.find_each do |org|
    add motorsport_event_organization_path(org), :changefreq => 'daily', :priority => 0.9, :lastmod => Time.now
  end

  Event.find_each do |event|
    add motorsport_event_organization_event_path(event.organization, event), :changefreq => 'daily', :priority => 1, :lastmod => event.event_date
  end

  Listing.active.each do |listing|
    add classifieds_listing_path(listing), :changefreq => 'daily', :priority => 1, :lastmod => listing.updated_at
  end

  add '/faq', :changefreq => 'monthly', :priority => 0.5, :lastmod => '2013-07-01'
  add '/how_it_works_for_buyers', :changefreq => 'yearly', :priority => 0.5, :lastmod => '2013-01-01'
  add '/how_it_works_for_sellers', :changefreq => 'yearly', :priority => 0.5, :lastmod => '2013-01-01'
  add '/buyer_faq', :changefreq => 'yearly', :priority => 0.5, :lastmod => '2013-01-01'
  add '/seller_faq', :changefreq => 'yearly', :priority => 0.5, :lastmod => '2013-01-01'
  add '/search', :changefreq => 'yearly', :priority => 0.5, :lastmod => '2013-01-01'


  ############
  # PARTNERS #
  ############

  add '/', :changefreq => 'monthly', :priority => 0.9, :lastmod => '2013-07-01', :host => 'https://partners.mysite.com'
  add '/blogs', :changefreq => 'monthly', :priority => 0.8, :lastmod => Blog.last.created_at, :host => 'https://partners.mysite.com'

  Blog.find_each do |blog|
    add partners_blog_path(blog), :priority => 1, :lastmod => Blog.last.created_at, :host => 'https://partners.mysite.com'
  end

  add '/pricing', :changefreq => 'monthly', :priority => 0.8, :lastmod => '2013-07-01', :host => 'https://partners.mysite.com'
  add '/faq', :changefreq => 'monthly', :priority => 0.5, :lastmod => '2013-07-01', :host => 'https://partners.mysite.com'
  add '/whoweare', :changefreq => 'yearly', :priority => 0.5, :lastmod => '2012-01-01', :host => 'https://partners.mysite.com'
  add '/workwithus', :changefreq => 'monthly', :priority => 0.5, :lastmod => '2012-01-01', :host => 'https://partners.mysite.com'
  add '/contactus', :priority => 0.5, :lastmod => '2012-01-01', :host => 'https://partners.mysite.com'

end

当我在生产环境中运行 rake 任务时，出现上述错误。这是整个堆栈跟踪：

rake sitemap:refresh --trace

** Invoke sitemap:refresh (first_time)
** Invoke sitemap:create (first_time)
** Invoke sitemap:require_environment (first_time)
** Execute sitemap:require_environment
** Invoke environment (first_time)
** Execute environment
** Execute sitemap:create

rake aborted!
private method `split' called for nil:NilClass
/shared/bundled_gems/ruby/1.8/gems/subdomain-fu-0.5.4/lib/subdomain-fu.rb:65:in `host_without_subdomain'
/shared/bundled_gems/ruby/1.8/gems/subdomain-fu-0.5.4/lib/subdomain-fu.rb:85:in `change_subdomain_of_host'
/shared/bundled_gems/ruby/1.8/gems/subdomain-fu-0.5.4/lib/subdomain-fu.rb:72:in `rewrite_host_for_subdomains'
/shared/bundled_gems/ruby/1.8/gems/subdomain-fu-0.5.4/lib/subdomain_fu/url_rewriter.rb:6:in `url_for'
(eval):17:in `motorsport_event_organization_path'
/releases/20130720225723/config/sitemap.rb:13:in `run'
/shared/bundled_gems/ruby/1.8/gems/activerecord-2.3.16/lib/active_record/batches.rb:26:in `find_each'
/shared/bundled_gems/ruby/1.8/gems/activerecord-2.3.16/lib/active_record/batches.rb:26:in `each'
/shared/bundled_gems/ruby/1.8/gems/activerecord-2.3.16/lib/active_record/batches.rb:26:in `find_each'
/shared/bundled_gems/ruby/1.8/gems/activerecord-2.3.16/lib/active_record/batches.rb:66:in `find_in_batches'
/shared/bundled_gems/ruby/1.8/gems/activerecord-2.3.16/lib/active_record/batches.rb:25:in `find_each'
/releases/20130720225723/config/sitemap.rb:12:in `run'
/shared/bundled_gems/ruby/1.8/gems/sitemap_generator-4.1.1/lib/sitemap_generator/interpreter.rb:59:in `instance_eval'
/shared/bundled_gems/ruby/1.8/gems/sitemap_generator-4.1.1/lib/sitemap_generator/interpreter.rb:59:in `eval'
/shared/bundled_gems/ruby/1.8/gems/sitemap_generator-4.1.1/lib/sitemap_generator/link_set.rb:39:in `create'
/shared/bundled_gems/ruby/1.8/gems/sitemap_generator-4.1.1/lib/sitemap_generator.rb:33:in `send'
/shared/bundled_gems/ruby/1.8/gems/sitemap_generator-4.1.1/lib/sitemap_generator.rb:33:in `method_missing'
/releases/20130720225723/config/sitemap.rb:2:in `run'
/shared/bundled_gems/ruby/1.8/gems/sitemap_generator-4.1.1/lib/sitemap_generator/tasks.rb:51
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/lib/rake.rb:636:in `call'
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/lib/rake.rb:636:in `execute'
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/lib/rake.rb:631:in `each'
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/lib/rake.rb:631:in `execute'
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/lib/rake.rb:597:in `invoke_with_call_chain'
/usr/lib/ruby/1.8/monitor.rb:242:in `synchronize'
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/lib/rake.rb:590:in `invoke_with_call_chain'
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/lib/rake.rb:607:in `invoke_prerequisites'
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/lib/rake.rb:604:in `each'
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/lib/rake.rb:604:in `invoke_prerequisites'
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/lib/rake.rb:596:in `invoke_with_call_chain'
/usr/lib/ruby/1.8/monitor.rb:242:in `synchronize'
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/lib/rake.rb:590:in `invoke_with_call_chain'
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/lib/rake.rb:583:in `invoke'
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/lib/rake.rb:2051:in `invoke_task'
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `top_level'
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `each'
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `top_level'
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling'
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/lib/rake.rb:2023:in `top_level'
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/lib/rake.rb:2001:in `run'
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling'
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/lib/rake.rb:1998:in `run'
/shared/bundled_gems/ruby/1.8/gems/rake-0.8.7/bin/rake:31
/shared/bundled_gems/ruby/1.8/bin/rake:19:

我在生产和开发之间找不到任何会导致这种情况的不同之处。您能提供的任何帮助将不胜感激！

编辑：我可能应该补充一点，生成路径似乎有问题。删除所有路径使这项工作正常。问题是路径是正确的，并且此代码在开发中运行良好。我不知道为什么路径不会在生产中生成。

编辑 2：这里是 development.rb：

require 'rack/ssl-enforcer'
require 'stripe'

config.middleware.use ::Rack::SslEnforcer, :except => /^\/api\//

# Settings specified here will take precedence over those in config/environment.rb

# In the development environment your application's code is reloaded on
# every request.  This slows down response time but is perfect for development
# since you don't have to restart the webserver when you make code changes.
config.cache_classes = false

# Log error messages when you accidentally call methods on nil.
config.whiny_nils = true

# Show full error reports and disable caching
config.action_controller.consider_all_requests_local = true
config.action_view.debug_rjs                         = true
config.action_controller.perform_caching             = false

# Don't care if the mailer can't send
config.action_mailer.raise_delivery_errors = false

config.after_initialize do
  ActionMailer::Base.delivery_method = :amazon_ses
  ActionMailer::Base.custom_amazon_ses_mailer = AWS::SES::Base.new(:secret_access_key => S3_CONFIG[:secret_access_key], :access_key_id => S3_CONFIG[:access_key_id])
end

# Default APP Domain
APP_DOMAIN = 'mysite.dev'
ActionMailer::Base.default_url_options[:host] = APP_DOMAIN

# ensure the sessions work across the subdomains
begin
  config.action_controller.session[:domain] = ".#{APP_DOMAIN}"
rescue
  config.action_controller.session = {:domain => ".#{APP_DOMAIN}"}
end

这是production.rb：

# Settings specified here will take precedence over those in config/environment.rb
require 'rack/ssl-enforcer'
require 'stripe'

config.middleware.use ::Rack::SslEnforcer, :except => /^\/api\//

# The production environment is meant for finished, "live" apps.
# Code is not reloaded between requests
config.cache_classes = true

# Full error reports are disabled and caching is turned on
config.action_controller.consider_all_requests_local = false
config.action_controller.perform_caching             = true
config.action_view.cache_template_loading            = true

# See everything in the log (default is :info)
# config.log_level = :debug

# Use a different logger for distributed setups
# config.logger = SyslogLogger.new

# Use a different cache store in production
# config.cache_store = :mem_cache_store

# Enable serving of images, stylesheets, and javascripts from an asset server
# config.action_controller.asset_host = "http://assets.example.com"

# Disable delivery errors, bad email addresses will be ignored
config.action_mailer.raise_delivery_errors = false

# Enable threaded mode
# config.threadsafe!

# Default APP Domain
APP_DOMAIN = 'mysite.com'
ActionMailer::Base.default_url_options[:host] = "www.#{APP_DOMAIN}"

# Amazon SES Mailer
config.after_initialize do
  ActionMailer::Base.delivery_method = :amazon_ses
  ActionMailer::Base.custom_amazon_ses_mailer = AWS::SES::Base.new(:secret_access_key => S3_CONFIG[:secret_access_key], :access_key_id => S3_CONFIG[:access_key_id])
end

# ensure the sessions work across the subdomains
begin
  config.action_controller.session[:domain] = ".#{APP_DOMAIN}"
rescue
  config.action_controller.session = {:domain => ".#{APP_DOMAIN}"}
end

prod 和 dev 环境不共享数据库。

Answer 1

这里的问题是，由于您在请求上下文之外运行 rake 任务，因此没有主机可供它操作。从来源：

异常发生在：https ://github.com/mbleigh/subdomain-fu/blob/v0.5.4/lib/subdomain-fu.rb#L65

我们可以看到它正在尝试拆分一个 nil 主机。按照堆栈跟踪到：https ://github.com/mbleigh/subdomain-fu/blob/v0.5.4/lib/subdomain_fu/url_rewriter.rb#L6

我们看到传入的主机是

options[:host] || default_url_options[:host]

通常，default_url_options[:host]将从请求的 Host 标头填充，但由于这是在请求之外，因此没有可操作的主机标头。您需要做的是：

1. default_url_options通过覆盖在您的应用程序控制器中设置默认主机：http: //guides.rubyonrails.org/action_controller_overview.html#default-url-options
2. 或者，将 :host 传递给您调用的路由选项motorsport_event_organization_path。

第一个选项可能是最简单的。

Answer 2

如果您定义，错误将消失：

def nil.split
  tap { warn "Stand back, splitting nil!" }
end