我是一个 ROR 新手，他继承了一个项目（Ruby 版本 1.9.3p0、Rails 版本 3.0.6、rake 版本 0.9.2），该项目执行 rake 作为 cronjob 的一部分。这一直在将“rake aborted！undefined method `[]=' for nil:NilClass”输出到其日志文件中。当我执行跟踪时，我得到以下输出：
rake aborted!
undefined method `[]=' for nil:NilClass
/var/www/nostos-source-illiad/lib/nostos-source-illiad/record.rb:48:in `block in charge!'
(eval):22:in `form_with'
/var/www/nostos-source-illiad/lib/nostos-source-illiad/record.rb:47:in `charge!'
/var/www/nostos/app/models/transaction.rb:65:in `block (2 levels) in sync!'
/var/www/nostos/app/models/transaction.rb:58:in `each'
/var/www/nostos/app/models/transaction.rb:58:in `block in sync!'
/var/www/nostos/app/models/transaction.rb:57:in `each'
/var/www/nostos/app/models/transaction.rb:57:in `sync!'
/var/www/nostos/lib/tasks/nostos.rake:17:in `block (2 levels) in <top (required)>'
/home/deployer/.rbenv/versions/1.9.3-p0/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:205:in `call'
/home/deployer/.rbenv/versions/1.9.3-p0/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:205:in `block in execute'
/home/deployer/.rbenv/versions/1.9.3-p0/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:200:in `each'
/home/deployer/.rbenv/versions/1.9.3-p0/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:200:in `execute'
/home/deployer/.rbenv/versions/1.9.3-p0/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:158:in `block in invoke_with_call_chain'
/home/deployer/.rbenv/versions/1.9.3-p0/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
/home/deployer/.rbenv/versions/1.9.3-p0/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:151:in `invoke_with_call_chain'
/home/deployer/.rbenv/versions/1.9.3-p0/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:144:in `invoke'
/home/deployer/.rbenv/versions/1.9.3-p0/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:112:in `invoke_task'
/home/deployer/.rbenv/versions/1.9.3-p0/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:90:in `block (2 levels) in top_level'
/home/deployer/.rbenv/versions/1.9.3-p0/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:90:in `each'
/home/deployer/.rbenv/versions/1.9.3-p0/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:90:in `block in top_level'
/home/deployer/.rbenv/versions/1.9.3-p0/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:129:in `standard_exception_handling'
/home/deployer/.rbenv/versions/1.9.3-p0/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:84:in `top_level'
/home/deployer/.rbenv/versions/1.9.3-p0/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:62:in `block in run'
/home/deployer/.rbenv/versions/1.9.3-p0/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:129:in `standard_exception_handling'
/home/deployer/.rbenv/versions/1.9.3-p0/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:59:in `run'
/home/deployer/.rbenv/versions/1.9.3-p0/lib/ruby/gems/1.9.1/gems/rake-0.9.2/bin/rake:32:in `<top (required)>'
/home/deployer/.rbenv/versions/1.9.3-p0/lib/ruby/gems/1.9.1/bin/rake:19:in `load'
/home/deployer/.rbenv/versions/1.9.3-p0/lib/ruby/gems/1.9.1/bin/rake:19:in `<main>'
Tasks: TOP => nostos:cron
我无法确定究竟是什么导致了这个问题，并且正在寻找一些建议/方向。我不认为这是由此处报告的相同问题引起的，但我不确定。任何帮助，将不胜感激。谢谢！
编辑：代码nostos:rake可以在这里找到。
代码transaction.rb可以在这里找到。