Fix redo_pyc for Python 3

src/zc/buildout/easy_install.py

@@ -1692,20 +1692,31 @@ def redo_pyc(egg):
         chmod(dirpath)
         for filename in filenames:
             filepath = os.path.join(dirpath, filename)
-            chmod(filepath)
+            try:
+                chmod(filepath)
+            except OSError as e:
+                if e.errno != errno.ENOENT:
+                    raise
+                continue
             if not filename.endswith('.py'):
                 continue
-            if not (os.path.exists(filepath+'c')
-                    or os.path.exists(filepath+'o')):
+
+            old = []
+            pycache = os.path.join(dirpath, '__pycache__',
+                                   filename[:-3] + '.*.py')
+            for suffix in 'co':
+                if os.path.exists(filepath + suffix):
+                    old.append(filepath + suffix)
+                old += glob.glob(pycache + suffix)
+            if not old:
                 # If it wasn't compiled, it may not be compilable
                 continue
 
             # OK, it looks like we should try to compile.
 
             # Remove old files.
-            for suffix in 'co':
-                if os.path.exists(filepath+suffix):
-                    os.remove(filepath+suffix)
+            for old in old:
+                os.remove(old)
 
             # Compile under current optimization
             try: