title: Python Gtk3 | Gtk.TextView() dies with pango_layout_new error
body: <p>My Python (2.7) + Gtk# + Windows 7 program is dying when calling the constructor for a Gtk.TextView:</p>
  
  <pre><code>t = Gtk.TextView()
  </code></pre>
  
  <p>And this error is printed to stderr:</p>
  
  <pre><code>  (python.exe:151468): Pango-CRITICAL **: pango_layout_new: assertion 'context != NULL' failed
  </code></pre>
  
  <p>This is only happening in a big complex program, and does not happen in a simple test script. I don't know what could be triggering it.</p>
  
  <p>(Errors printed out from within Gtk are really frustrating when using the Python bindings (gi.repository) because we cannot see what is going on or catch the exception...)</p>