lib/omnibus/project.rb
def install_dir(val = NULL)
      if null?(val)
        @install_dir || raise(MissingRequiredAttribute.new(self, :install_dir, "/opt/chef"))
      else
        @install_dir = val.tr('\\', "/").squeeze("/").chomp("/")
      end
    end
def install_dir(val = NULL)
      if null?(val)
        @install_dir || raise(MissingRequiredAttribute.new(self, :install_dir, "/opt/chef"))
      else
        @install_dir = val.tr('\\', "/").squeeze("/").chomp("/")
      end
    end
**[Required]** Set or retrieve the path at which the project should be
 installed by the generated package.

 Even on Windows-based systems, this path should be the Unix-like path,
 since that's what Ruby expects. In the event +\+ is used as a file
 separator, it will be replaced with +/+. This method also attempts to
 remove duplicate slashes which might be caused as a result of string
 interpolation.

 @example
   install_dir '/opt/chef'

 @raise [MissingRequiredAttribute] if a value was not set before being
   subsequently retrieved

 @param [String] val
   the install path to set

 @return [String]