don't need this anymore

SConstruct

@@ -1,5 +1,3 @@
-import Cython
-import distutils
 import os
 import shutil
 import subprocess
@@ -19,10 +17,6 @@ AddOption('--asan',
           action='store_true',
           help='turn on ASAN')
 
-# Rebuild cython extensions if python, distutils, or cython change
-cython_dependencies = [Value(v) for v in (sys.version, distutils.__version__, Cython.__version__)]
-Export('cython_dependencies')
-
 real_arch = arch = subprocess.check_output(["uname", "-m"], encoding='utf8').rstrip()
 if platform.system() == "Darwin":
   arch = "Darwin"