Start the appengine-tools gem

lib/appengine-tools/genxml.rb

 #!/usr/bin/ruby1.8 -w
 #
 # Copyright:: Copyright 2009 Google Inc.
 # Original Author:: Ryan Brown (mailto:ribrdb@google.com)
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #      http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
 require 'appengine-tools/web-xml'
 require 'appengine-tools/rack'
+require 'appengine-tools/xml-formatter'
 
 Dir.mkdir('WEB-INF') unless File.exists?('WEB-INF')
 rackup = File.read('config.ru')
 builder = WebXmlBuilder.new do
   eval rackup, nil, 'config.ru', 1
 end
-builder.write
+open('WEB-INF/web.xml', 'w') do |webxml|
+  xml = AppEngine::Rack::XmlFormatter.format(builder.to_xml)
+  webxml.write(xml)
+end
 open('WEB-INF/appengine-web.xml', 'w') do |aeweb|
-  aeweb.write(AppEngine::Rack.app.to_xml)
+  xml = AppEngine::Rack::XmlFormatter.format(AppEngine::Rack.app.to_xml)
+  aeweb.write(xml)
 end