:date: 2016-08-01

======================
Monday, August 1, 2016
======================

Today I didn't work very much (we came back from Saremaa), and that
time went into exploring some problems caused by upgrading my machine
from Ubuntu 14.04 to 16.04.
E.g. Python is now version 2.7.12 (it was 2.7.6)

Virtualenvs broken after upgrade to Ubuntu 16.04
================================================

This one looked rather spectacular::
  
    $ python -m datetime
    Traceback (most recent call last):
      File ".../virtualenvs/py27/lib/python2.7/site.py", line 703, in <module>
        main()
      ...
      File ".../virtualenvs/py27/local/lib/python2.7/site-packages/coverage/html.py", line 6, in <module>
        import datetime
    ImportError: No module named datetime

The solution was to remove and re-create the virtual environment.

After reading `this
<https://stackoverflow.com/questions/36796887/virtualenv-python-broke-after-upgrading-ubuntu-15-10-to-16-04>`_
I guess that the explanation is that yes, virtualenvs rely on the
paths of your Python intallation, and thus they can break when you
upgrade to some new Debian version.

Atelier no longer needs Fabric
==============================

When using the new virtual environment, I noticed that some parts of
:ref:`atelier` still depended on Fabric.  I removed this dependency by
deactivating :meth:`atelier.projects.Project.load_fabfile`.


Problem with for loops in :term:`appy.pod`
==========================================

Another problem occured later during :cmd:`inv prep` in
:ref:`welfare`::

    appy.pod render /media/dell1tb/luc/work/welfare/lino_welfare/modlib/isip/config/isip/Contract/Default.odt -> ~/tmp/lino_cache/welfare_std/media/webdav/userdocs/appyodt/isip.Contract-1.odt (language='en',params={'raiseOnError': True, 'ooPort': 8100, 'pythonWithUnoPath': u'/usr/bin/python3'}
    Traceback (most recent call last):
      File "~/virtualenvs/py27/bin/django-admin.py", line 5, in <module>
        management.execute_from_command_line()
      ...
    appy.pod.actions.EvaluationError: Problem installing fixture '~/luc/work/xl/lino_xl/lib/excerpts/fixtures/demo2.py': Error while evaluating expression "row.company". 
       File "~/virtualenvs/py27/local/lib/python2.7/site-packages/appy/pod/buffers.py", line 702, in evaluate
        res, escape = evalEntry.evaluate(context)
       File "~/virtualenvs/py27/local/lib/python2.7/site-packages/appy/pod/elements.py", line 144, in evaluate
        res = self._eval(context)
       File "~/virtualenvs/py27/local/lib/python2.7/site-packages/appy/pod/elements.py", line 125, in _eval
        res = eval(self.expr, context)
       File "<string>", line 1, in <module>
     <type 'exceptions.NameError'>: name 'row' is not defined

I can cheat the test suite by setting `raiseOnError=False`, but that's
not a solution. A first observatio
is that the problem disappeared after doing::

  $ pip install 'appy==0.9.3'

Which means that version 0.9.4 of :term:`appy.pod` is the "guilty".
Gaetan has done a lot of work in Appy, some of it probably very useful
for Lino. I scanned through his release notes for `0.9.4
<https://launchpad.net/appy/0.9/0.9.4>`_, but at first glance I did
not see any obvious reason for our problem. Needs more investigation.
I created :ticket:`1089` for this.


A new RSS feed generator for my blog
====================================

A third problem caused by the new virtualenv was when running
:cmd:`inv bd` in my :ref:`blog`::

    Extension error:
    Could not import extension sphinxcontrib.feed (exception: No module named feed)

First I had to find out how to install ``sphinxcontrib.feed``. Because
"pip install sphinxcontrib.feed" does not work. I had to clone
`sphinx-contrib <https://bitbucket.org/birkenfeld/sphinx-contrib>`_
and to do::

  $ cd ~/repositories/sphinx-contrib/feed
  $ python setup.py build
  $ python setup.py install

This fixed the first exception, but then I had yet another exception
during :cmd:`inv bd` in my blog::

    Exception occurred:
      File "~/virtualenvs/py27/lib/python2.7/site-packages/feed-0.3a0.dev20160801-py2.7.egg/sphinxcontrib/feed/absolutify_urls.py", line 72, in absolutify
        html_serializer = html5lib.serializer.htmlserializer.HTMLSerializer()
    AttributeError: 'module' object has no attribute 'htmlserializer'

I could not find anything helpful neither in the `html5lib
documentation <http://html5lib.readthedocs.io/en/latest/index.html>`_
nor in the code of :file:`sphinxcontrib/feed/absolutify_urls.py`.

Since I was locked, I checked whether there is some other RSS feed
generator for Sphinx which gives the same result. 

I tried `yasfb <https://pypi.python.org/pypi/yasfb>`_, but that's not
what I want. There are almost 2000 pages in my blog's doctree and I
definitively don't want to have an RSS item for each of them.

Finally I opted to take `Fergus Doyle's sphinxfeed
<https://github.com/junkafarian/sphinxfeed>`_. The only problem here
was that sphinxfeed expects a meta variable named ``:Publish Date:``
at the beginning of each blog entry, while my blog files use the
``:date`` meta variable. And I didn't want to change them all.  So I
forked the project, added add a new config variable `feed_field_name`
and sent Fergus a `pull request
<https://github.com/junkafarian/sphinxfeed/pull/2>`_.  I'll now wait
for his feedback.


Alt-Tab and the Application Switcher
====================================

After the Ubuntu upgrade, :kbd:`Alt-Tab` did not work as I am used it
to work. It switches to the next window without displaying any
intermediate list of open windows. I had to install this::
     
  $ sudo apt install compizconfig-settings-manager
  $ ccsm

And then I found under "Window Management" an option "Application
Switcher" which was disabled. I enabled it, confirmed some questions
about some conflict with some Ubuntu Plugin, and then it worked again.

     
Anpassungen
===========

I solved ticket :ticket:`1088` and deployed that version to
:ref:`eiche`. It didn't even need a database migration since all the
fields were already there.