increase time suggected here:
https://github.com/cherrypy/cherrypy/issues/1896

--- a/cherrypy/test/test_static.py
+++ b/cherrypy/test/test_static.py
@@ -76,7 +76,7 @@
         class Root:
 
             @cherrypy.expose
-            @cherrypy.config(**{'response.stream': True})
+            @cherrypy.config(**{'response.stream': True, 'server.socket_timeout': 5})
             def bigfile(self):
                 self.f = static.serve_file(bigfile_filepath)
                 return self.f