= Proposed System Wide Change: Python 3.4 =
https://fedoraproject.org/wiki/Changes/Python_3.4
Change owner(s): Slavek Kabrda <bkabrda(a)redhat.com>
Update the Python 3 stack in Fedora from Python 3.3 to Python 3.4.
== Detailed description ==
Python 3.4 adds numerous features and optimizations. See the upstream notes at
http://www.python.org/dev/peps/pep-0429/#features-for-3-4 and
http://docs.python.org/dev/whatsnew/3.4.html.
== Scope ==
Compare with the Python 3.3 feature page [1].
We need to wait for Python 3.4 to reach feature freeze (planned for 3.4.0 beta
1: November 24, 2013), so that the bytecode format for .pyc files is frozen,
together with the ABI for extension modules.
At that point we can rebase python3 to the latest release candidate of that
code. We would then need to rebuild all python 3 packages. See
https://fedoraproject.org/wiki/Python3#Python_3_already_in_Fedora
For bonus points, we ought to tell "file" and "rpmlint" about the new
bytecode
format for .pyc files.
Note that the suffix of some files should change, and this may require slight
packaging tweaks in the various packages that ship Python 3 code:
* bytecode files changing from .cpython-33.pyc (and .cpython-33.pyo) to
.cpython-34.pyc (and .cpython-34.pyo)
* extension modules changing from .cpython-33m.so to .cpython-34m.so and
.cpython-33dm.so to .cpython-34dm.so
Notes about porting from Python 3.3 can be found at
http://docs.python.org/dev/whatsnew/3.4.html#porting-to-python-3-4.
Proposal owners: This change is isolated to Python 3 stack, which is not yet
crucial for Fedora. Still, as the time of moving Fedora to Python 3 is
hopefully approaching, we need to do this very cautiously. I will prepare
Python 3.4 prerelease RPMs in a private repo and will do a test rebuild of all
Python 3 dependent packages, filing bugs/sending patches to upstreams. This
will give us a good notion of how drastic this change will be and whether or
not we really want to undergo it. Overall, the change should have roughly this
schedule:
* After change is accepted: Start building Python 3.4 prereleases in a private
repo, continuously upgrading with latest upstream prerelease versions.
* November 24, 2013 (3.4.0 beta 1: feature freeze): Start rebuilding Python 3
dependent packages in the repo.
* February 23, 2014 (3.4.0 final) If everything goes well (meaning that all
essential packages in Fedora build and work with Python 3.4) up to this point,
merge into F21.
Other developers: I'll gladly accept any help with
rebuilding/porting/patching/bug reporting of dependent packages as well as
suggestions for Python 3.4 packaging itself. When we're sure that we really
want to do the transition, it'd be great if package owners rebuilt their
packages themselves.
Release engineering: Nothing.
Policies and guidelines: None.
[1]
https://fedoraproject.org/wiki/Features/Python_3.3