         # File lib/rake.rb, line 291
    291:     def dup
    292:       sibling = self.class.new
    293:       instance_variables.each do |ivar|
    294:         value = self.instance_variable_get(ivar)
    295:         new_value = value.clone rescue value
    296:         sibling.instance_variable_set(ivar, new_value)
    297:       end
    298:       sibling.taint if tainted?
    299:       sibling
    300:     end