Fix Python 2.7 mac on Travis.

See pypa/virtualenv#1555

Also fix 64-bit windows Python 2; apparently the documentation I read was outdated.

.travis.yml

@@ -104,10 +104,10 @@ script:
   # coverage makes PyPy run about 3x slower, but the tests only take
   # .4s to begin with (the whole process takes about 1.5), so that's
   # still only 4.5s, which is maneagable.
-  - coverage run -m zope.testrunner --test-path=. --auto-color --auto-progress
+  - python -m coverage run -m zope.testrunner --test-path=. --auto-color --auto-progress
 
 after_success:
-  - coveralls
+  - python -m coveralls
   - |
     if [[ $TRAVIS_TAG && "$TRAVIS_OS_NAME" == "osx" ]]; then
       pip install twine

persistent/list.py

@@ -23,6 +23,7 @@
 # The slice object you get when you write list[:]
 _SLICE_ALL = slice(None, None, None)
 
+
 class PersistentList(UserList, persistent.Persistent):
     """A persistent wrapper for list objects.
 
@@ -72,8 +73,16 @@ def __setslice__(self, i, j, other):
             self._p_changed = 1
 
         def __delslice__(self, i, j):
-            # For list[:], i and j become 0 and sys.maxint
-            needs_changed = i == 0 and j == sys.maxint and bool(self)
+            # On Python 2, the slice dunders, like ``__delslice__``,
+            # are documented as getting ``(0, sys.maxsize)`` as the
+            # arguments for list[:]. Prior to 2.7.10, it was
+            # incorrectly documented as ``(0, sys.maxint)``, but that
+            # usually worked because ``sys.maxsize`` and
+            # ``sys.maxint`` are usually the same. But on 64-bit
+            # Windown, where ``sizeof(int) == sizeof(long) == 4``,
+            # they're different (``sys.maxsize`` is bigger). See
+            # https://bugs.python.org/issue23645
+            needs_changed = i == 0 and j == sys.maxsize and bool(self)
             self.__super_delslice(i, j)
             if needs_changed:
                 self._p_changed = 1