On 18 Jun 2015 10:02 pm, "Matej Stuchlik" <mstuchli@redhat.com> wrote:
> We feel that that's perhaps a little tight schedule, where things could
> go wrong easily. For that reason we'd like stay with Python 3.4 as system
> python for Fedora 23, while providing Python 3.5 in a Copr. (Perhaps using
> Miro's repo)
>
> Does that make sense?

It does. I also realised last night that there's a better, less disruptive path forward that relates to a discussion we had upstream at this year's language summit regarding the Python 3 transition and /usr/bin/python on POSIX systems: https://lwn.net/Articles/640296/

The idea I had in relation to that is to wonder whether we could come up with a self-contained change that allowed the normal python symlink to be swapped out for a configurable version switcher that was compatible with the distro independent environment module system now used for SCLs.

That approach would start us down the path of better separating the "system default Python" setting from the choice of "user's preferred Python", paving the way for users swapping in alternative implementations like PyPy and Jython, in addition to choosing between CPython 2.7, 3.4 & 3.5.

Cheers,
Nick.

P.S. There's at least one current compatibility issue in the upstream Python test suite related to Fedora's upgrade to more secure default SSL settings: http://bugs.python.org/issue23965