Most likely you run rake and your code is causing an exception which is not the one shown in your terminal.

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Rails tries to catch this exception and clean up constants but -- while it's still booting up -- fails on this which causes another exception:

rake aborted!
cannot remove Object::ClassMethods

Running rake with the --trace parameter will give you no love; the backtrace is useless in most cases.

Try these approaches:

First: Check if there is a helpful error message

• Have a look at the environment's log file instead
• Open up a Rails console (may give you more information than the logs)

If you're lucky it's a helpful message, like a missing database. Unfortunately, the error often is too generic and you don't know where it originates from.

If that won't work: Dig really deep

In any case, Rails usually breaks on the blame_file! call where it tries to show you the source of the error. You can (temporarily) hack Rails' require call in .../gems/activesupport-2.3.12/lib/active_support/dependencies.rb and show the error before Rails gets it into its hands:

  def require(file, *extras)
    if Dependencies.load?
      Dependencies.new_constants_in(Object) { super }
    else
      super
    end
  rescue Exception => exception
    puts "ERROR: '#{exception}' in #{file}" # This is new.
    exception.blame_file! file
    raise
  end

When you rake --trace after that you may see some "no such file to load" issues (which usually stay hidden) but should also see the file causing the actual error.