title: Why is kivy unable to import kivy_clock?
body: <p><a href="https://kivy.org/doc/stable/api-kivy.app.html" rel="nofollow noreferrer">https://kivy.org/doc/stable/api-kivy.app.html</a></p>
  
  <pre><code>import kivy
  
  kivy.require('1.0.7')
  
  from kivy.app import App
  
  from kivy.uix.button import Button
  
  
  class TestApp(App):
  
  def build(self):
      # return a Button() as a root widget
      return Button(text='hello world')
  
  
  if __name__ == '__main__':
      TestApp().run()
  </code></pre>
  
  <p><strong>according to the above codes i have the following error</strong> </p>
  
  <pre><code>[INFO   ] [Logger      ] Record log in C:\Users\USER\.kivy\logs\kivy_20-05-09_45.txt
  [INFO   ] [deps        ] Successfully imported "kivy_deps.angle" 0.1.10
  [INFO   ] [Kivy        ] v1.11.1
  [INFO   ] [Kivy        ] Installed at "C:\Users\USER\AppData\Local\Programs\Python\Python38-32\lib\site-packages\kivy\__init__.py"
  [INFO   ] [Python      ] v3.8.1 (tags/v3.8.1:1b293b6, Dec 18 2019, 22:39:24) [MSC v.1916 32 bit (Intel)]
  [INFO   ] [Python      ] Interpreter at "C:\Users\USER\AppData\Local\Programs\Python\Python38-32\python.exe"
  [ERROR  ] [Clock       ] Unable to import kivy._clock. Have you perhaps forgotten to compile kivy? Kivy contains Cython code which needs to be compiled. A missing kivy._clock often indicates the Cython code has not been compiled. Please follow the installation instructions and make sure to compile Kivy
   Traceback (most recent call last):
     File "C:/Users/USER/PycharmProjects/Hello world/pop.py", line 4, in &lt;module&gt;
       from kivy.app import App
     File "C:\Users\USER\AppData\Local\Programs\Python\Python38-32\lib\site-packages\kivy\app.py", line 319, in &lt;module&gt;
       from kivy.base import runTouchApp, stopTouchApp
     File "C:\Users\USER\AppData\Local\Programs\Python\Python38-32\lib\site-packages\kivy\base.py", line 26, in &lt;module&gt;
       from kivy.clock import Clock
     File "C:\Users\USER\AppData\Local\Programs\Python\Python38-32\lib\site-packages\kivy\clock.py", line 363, in &lt;module&gt;
       from kivy._clock import CyClockBase, ClockEvent, FreeClockEvent, \
   ModuleNotFoundError: No module named 'kivy._clock'
  </code></pre>
  
  <p>I think there is a problem with the kivy_clock and Cython.</p>