IPython/Jupyter plans for buster

[Gordon Ball <gordon@chronitis.net>]

Hello

We currently have IPython 5.1 in the archive.

Upstream has announced [1][2] IPython/Jupyter 5.x as an LTS branch (36
months support, ending July 2019), and the last version to support
Python 2.7. The first releases of IPython 6 (supporting Python 3 only)
are now available.

There seem to be several possibilities:

 * Stick with 5.x only for this cycle
 * Stick with 5.x as the default for 2 and 3 and provide an alternative
6.x package for python 3
 * Stick with 5.x only for python 2.7 and create a separate ipython 6.x
source package for python 3

This decision probably only needs to be made for the "user visible"
components of jupyter (ipython, ipykernel and their dependencies); the
application/script parts (nbconvert, jupyter-notebook, qtconsole, etc)
can probably be moved to be python 3 only when required.

Gordon

[1]:
https://github.com/jupyter/roadmap/blob/master/accepted/migration-to-python-3-only.md
[2]: http://www.python3statement.org/

postscript: I've just pushed updates to git for several of the jupyter
packages
 * ipython -> 5.4.0
 * jupyter-client -> 5.1.0
 * nbconvert -> 5.2.1 (blocked on pandocfilters >= 1.4)
 * ipykernel -> 4.6.1