耙中止！ :name:Symbol 的未定义方法“map”

Posted 2023-02-24

【中文标题】耙中止！ :name:Symbol 的未定义方法“map”

【英文标题】：rake aborted! undefined method `map' for :name:Symbol

【发布时间】：2012-09-11 16:20:27

【问题描述】：

我正在尝试将参数传递给 Rake 任务并访问我的模型，如“How to pass command line arguments to a rake task”和“Do rails rake tasks provide access to ActiveRecord models?”中所述。

但是在此代码中添加=> :environment：

require 'rake'

namespace :genre do
    desc "Add a genre"
    task :add, :genre_id, :name => :environment do |t, args|
        puts args.name  
    end
end

运行任务时给我这个错误：

rake genre:add['1','Abc']
rake aborted!
undefined method `map' for :name:Symbol

(See full trace by running task with --trace)

如果我删除=> :environment，它就可以正常工作。

---

更新：

追踪：

rake --trace genre:add['1','Abc']
rake aborted!
undefined method `map' for :name:Symbol
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/rake-0.9.2.2/lib/rake/task.rb:254:in `set_arg_names'
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/rake-0.9.2.2/lib/rake/task_manager.rb:29:in `define_task'
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/rake-0.9.2.2/lib/rake/task.rb:310:in `define_task'
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/rake-0.9.2.2/lib/rake/dsl_definition.rb:32:in `task'
/private/var/www/html/someapp.com/subdomains/someapp.heroku.com/someapp/lib/tasks/genre.rake:5:in `block in <top (required)>'
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/rake-0.9.2.2/lib/rake/task_manager.rb:207:in `in_namespace'
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/rake-0.9.2.2/lib/rake/dsl_definition.rb:102:in `namespace'
/private/var/www/html/someapp.com/subdomains/someapp.heroku.com/someapp/lib/tasks/genre.rake:3:in `<top (required)>'
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/railties-3.2.3/lib/rails/engine.rb:425:in `load'
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/railties-3.2.3/lib/rails/engine.rb:425:in `block in load_tasks'
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/railties-3.2.3/lib/rails/engine.rb:425:in `each'
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/railties-3.2.3/lib/rails/engine.rb:425:in `load_tasks'
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/railties-3.2.3/lib/rails/application.rb:145:in `load_tasks'
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/railties-3.2.3/lib/rails/railtie/configurable.rb:30:in `method_missing'
/private/var/www/html/someapp.com/subdomains/someapp.heroku.com/someapp/Rakefile:7:in `<top (required)>'
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/rake-0.9.2.2/lib/rake/rake_module.rb:25:in `load'
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/rake-0.9.2.2/lib/rake/rake_module.rb:25:in `load_rakefile'
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/rake-0.9.2.2/lib/rake/application.rb:501:in `raw_load_rakefile'
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/rake-0.9.2.2/lib/rake/application.rb:82:in `block in load_rakefile'
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/rake-0.9.2.2/lib/rake/application.rb:81:in `load_rakefile'
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/rake-0.9.2.2/lib/rake/application.rb:65:in `block in run'
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/rake-0.9.2.2/lib/rake/application.rb:63:in `run'
/Users/user/.rvm/gems/ruby-1.9.2-p318/gems/rake-0.9.2.2/bin/rake:33:in `<top (required)>'
/Users/user/.rvm/gems/ruby-1.9.2-p318/bin/rake:19:in `load'
/Users/user/.rvm/gems/ruby-1.9.2-p318/bin/rake:19:in `<main>'

【参考方案1】：

看起来您的语法已关闭。试试：

task :add, [:genre_id, :name] => :environment do |t, args| 

【讨论】：

第一：效果很好。第二个给出：警告：'task :t, arg, :needs => [deps]' 已被弃用。请改用 'task :t, [args] => [deps]'。

不要使用 :needs... 只使用任务 :foo, [:arg1, :arg2] => [:bar]