Prepare 21.4.0

Author: hynek

CHANGELOG.rst

@@ -17,16 +17,23 @@ Whenever there is a need to break compatibility, it is announced here in the cha
 
    However if you intend to build extensions on top of ``attrs`` you have to anticipate that.
 
-Changes for the upcoming release can be found in the `"changelog.d" directory <https://github.com/python-attrs/attrs/tree/main/changelog.d>`_ in our repository.
+.. towncrier release notes start
+
+21.4.0 (2021-12-29)
+-------------------
+
+Changes
+^^^^^^^
 
-..
-   Do *NOT* add changelog entries here!
+- Fixed the test suite on PyPy3.8 where ``cloudpickle`` does not work.
+  `#892 <https://github.com/python-attrs/attrs/issues/892>`_
+- Fixed ``coverage report`` for projects that use ``attrs`` and don't set a ``--source``.
+  `#895 <https://github.com/python-attrs/attrs/issues/895>`_,
+  `#896 <https://github.com/python-attrs/attrs/issues/896>`_
 
-   This changelog is managed by towncrier and is compiled at release time.
 
-   See https://github.com/python-attrs/attrs/blob/main/.github/CONTRIBUTING.md#changelog for details.
+----
 
-.. towncrier release notes start
 
 21.3.0 (2021-12-28)
 -------------------

changelog.d/892.change.rst

@@ -24,7 +24,7 @@
 from ._version_info import VersionInfo
 
 
-__version__ = "21.4.0.dev0"
+__version__ = "21.4.0"
 __version_info__ = VersionInfo._from_version_string(__version__)
 
 __title__ = "attrs"