[Python-modules-team] Bug#671363: ipython-qtconsole: Wrong dependency for ipython-qtconsole

[Olivier Aubert]

Package: ipython-qtconsole
Version: 0.12-1
Severity: normal

Dear Maintainer,

While trying to test ipython-qtconsole, I stumbled on the following error message:

  File "/usr/lib/python2.7/dist-packages/IPython/external/qt.py", line 62, in <module>
    from PySide import QtCore, QtGui, QtSvg
ImportError: cannot import name QtGui

python-qt4 is installed (4.9.4) and python-pyside.qtcode as well (1.1.0-2). 
This seems to be related to https://github.com/ipython/ipython/issues/655 
since using the advised command line:

QT_API=pyqt ipython qtconsole 

works.  However, the patch mentionned in the cited bug report has been applied to the 
ipython version that I am running (looking at the code), so it is not exactly the same
issue. In fact, there are missing dependencies (python3-pyside.qtgui and
python3-pyside.qtsvg). This comes from the fact that the dependencies are
wrongly expressed. The Depends: states

         python3-pyqt4 | python3-pyside.qtcore,
         python3-pyqt4 | python3-pyside.qtgui,
         python3-pyqt4 | python3-pyside.qtsvg,

which (if the Depends: syntax allowed it, which is not the case) should rather be

 python3-pyqt4 | ( python3-pyside.qtcore, python3-pyside.qtgui, python3-pyside.qtsvg)

or could be factorized as

 python3-pyqt4 | ( python3-pyside.qtgui, python3-pyside.qtsvg)

since qtcore is required by qtgui and qtsvg.

I guess there is no immediate solution. Here are some ideas:

The pyside dependency could be expressed as
 python3-pyqt4 | python-pyside
but this would bring a number of unneeded components. 

A dummy package could be built, with dependencies on python3-pyside.qtcore,
python3-pyside.qtgui, python3-pyside.qtsvg, and then the Depends: would become
 python3-pyqt4 | python4-pyside-gui-svg-required-dummy-package
but this is not clean at all.

Finally, the IPython/external/qt.py file could be patched to address this issue:
try to import QtGui/QtSvg is nothing was specified in the env. variable, and then 
fallback on qtcore.

Regards,
Olivier

-- System Information:
Debian Release: wheezy/sid
  APT prefers testing
  APT policy: (990, 'testing'), (500, 'unstable')
Architecture: i386 (i686)

Kernel: Linux 3.2.0-2-686-pae (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=C (charmap=ANSI_X3.4-1968)
Shell: /bin/sh linked to /bin/dash

Versions of packages ipython-qtconsole depends on:
ii  ipython               0.12-1
ii  python                2.7.2-10
ii  python-pygments       1.5+dfsg-1
ii  python-pyside.qtcore  1.1.0-2
ii  python-qt4            4.9.1-1
ii  python-zmq            2.1.11-1
ii  python2.6             2.6.7-4
ii  python2.7             2.7.2-8

ipython-qtconsole recommends no packages.

ipython-qtconsole suggests no packages.

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