lib/omnibus/packagers/pkg.rb
def write_distribution_file
      render_template(resource_path("distribution.xml.erb"),
        destination: "#{staging_dir}/Distribution",
        mode: 0600,
        variables: {
          friendly_name: project.friendly_name,
          identifier: safe_identifier,
          version: safe_version,
          component_pkg: component_pkg,
        }
      )
    end
def write_distribution_file
      render_template(resource_path("distribution.xml.erb"),
        destination: "#{staging_dir}/Distribution",
        mode: 0600,
        variables: {
          friendly_name: project.friendly_name,
          identifier: safe_identifier,
          version: safe_version,
          component_pkg: component_pkg,
        }
      )
    end
Write the Distribution file to the staging area. This method generates the
 content of the Distribution file, which is used by +productbuild+ to
 select the component packages to include in the product package.

 It also includes information used to customize the UI of the Mac OS X
 installer.

 @return [void]