- Update to v4.5.1
+ Use pyproject.toml to specify build dependencies. This requires pip
18 or later to build from source.
- 4.5.0
+ Add support for Python 3.6 and 3.7, and drop support for Python 3.3.
+ Raise an ``ImportError`` consistently on Python 3 if the C extension for
BTrees is used but the ``persistent`` C extension is not available.
Previously this could result in an odd ``AttributeError``.
+ Fix the possibility of a rare crash in the C extension when
deallocating items.
+ Respect the ``PURE_PYTHON`` environment variable at runtime even if
the C extensions are available.
+ Always attempt to build the C extensions, but make their success
optional.
+ Fix a ``DeprecationWarning`` that could come from I and L objects in
Python 2 in pure-Python mode.
- Use %license (forwarded request 673139 from jayvdb)