...

src/calibre/ebooks/oeb/display/test-cfi/run.py

@@ -10,11 +10,11 @@ __docformat__ = 'restructuredtext en'
 import os
 
 try:
-    from calibre.utils.coffeescript import serve
+    from calibre.utils.serve_coffee import serve
 except ImportError:
     import init_calibre
     if False: init_calibre, serve
-    from calibre.utils.coffeescript import serve
+    from calibre.utils.serve_coffee import serve
 
 def run_devel_server():
     os.chdir(os.path.dirname(os.path.abspath(__file__)))

src/calibre/utils/serve_coffee.py

@@ -12,6 +12,11 @@ Utilities to help with developing coffeescript based apps.
 A coffeescript compiler and a simple web server that automatically serves
 coffeescript files as javascript.
 '''
+import sys
+if sys.version_info.major > 2:
+    print('This script is not Python 3 compatible. Run it with Python 2',
+            file=sys.stderr)
+    raise SystemExit(1)
 
 import time, SimpleHTTPServer, SocketServer, os, sys, re
 from io import BytesIO