[Python-modules-team] Bug#862315: ipython: [regression] IPython 5.x is very slow to start up

[Ben Longbons]

Package: ipython
Version: 5.1.0-3
Severity: important
Tags: upstream

Dear Maintainer,

Stretch is shipping with ipython 5, which has a major performance
regression compared to previous versions. (not yet fixed in ipython 6)

Startup time has increased from about 1 second (already slow, but tolerable)
to at least 2.5 seconds (my own), and possibly 10 seconds (some reports).

As a workaround, users can use:

neverrunpipasroot at host$ python2 -m pip install --user 'IPython==4.*'
neverrunpipasroot at host$ python3 -m pip install --user 'IPython==4.*'


The upstream issue is https://github.com/ipython/ipython/issues/9908

(The actual issue lies somewhere in pygments, which is a new dependency).

-Ben


-- System Information:
Debian Release: 9.0
  APT prefers unstable-debug
  APT policy: (500, 'unstable-debug'), (500, 'unstable'), (1, 'experimental')
Architecture: amd64
 (x86_64)
Foreign Architectures: i386, x32, arm64

Kernel: Linux 4.9.0-2-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages ipython depends on:
ii  python-ipython  5.1.0-3

ipython recommends no packages.

ipython suggests no packages.

-- no debconf information