title: Error in Kivy "Revision format must be X.Y.Z[-tag]"
body: <p>I try to run mi program but for some reason i see this error: "Revision format must be X.Y.Z[-tag]"
  I dont know what it means. </p>
  
  <p>I have been trying to take some things out of my code to know what is causing it but i havent figured it out yet</p>
  
  <p>Here is my python file:</p>
  
  <pre><code>#!/usr/bin/python
  import kivy
  from kivy.app import App
  from kivy.uix.label import Label
  from kivy.uix.boxlayout import BoxLayout
  from kivy.uix.screenmanager import ScreenManager, Screen
  kivy.require("1.11.1")
  
  class Inicial(BoxLayout):
      def __init__(self, **kwargs):
          super(Inicial, self).__init__(**kwargs)
          temperaturaActual = "°C"
  
  
  class MainApp(App):
      def build(self):
          return Inicial
  
  if __name__=="__main__":
      MainApp().run()
  </code></pre>
  
  <p>Here is my kv file:</p>
  
  <pre><code>#:kivy !
  
  #:kivy !
  
  &lt;Inicial&gt;:
      Label:
          id: "temperatura"
          text: root.temperaturaActual
          size_hint: (.25, .25)
          pos_hint: { 'center_x': .05, 'center_y': .55}
          font_size: 60sp
          font_name: 'C:/Users/mateo/AppData/Local/Microsoft/Windows/Fonts/Roboto-Light'
  </code></pre>