=================================
20130409 (Tuesday, 09 April 2013)
=================================

I moved from my 4-year-old Acer Aspire 7000 with Windows XP 
to a HP ProBook 4540s with Ubuntu for my daily work.
This revealed some minor problems like stray CR-LF newlines 
in some files.

These ones took me quite some time although the reason is rather 
the new Django version than the new environment:

- The exceptions "Using remote authentication, but no user credentials 
  found" and "Unknown or inactive username %r. Please contact your 
  system administrator" raised by 
  :class:`lino.utils.auth.RemoteUserMiddleware`
  were `PermissionDenied`. This caused Django 1.5 to not show 
  the exception's message at all, even on a development server 
  with DEBUG set to True. Now it's again a "normal" Exception,
  causing an email to the admins if it happens.

Django 1.5 and the SECRET_KEY setting
-------------------------------------

Many tests failed under Django 1.5 because it refuses an empty 
SECRET_KEY setting.

I created :djangoticket:`20227` 
"Accept an empty SECRET_KEY when DEBUG is True",
but they didn't agree.
So I need to either update all test cases and instructions 
or set a trivial default value for it. 
I choose the latter, at least as long as there is no better solution.
 

How to login through ssh without typing your password each time
---------------------------------------------------------------

On the client (the machine from which I want to login to 
a remote server)::

    (py27)luc@hoppel:~$ ssh-keygen -t dsa -f .ssh/id_dsa -P ''
    Generating public/private dsa key pair.
    Your identification has been saved in .ssh/id_dsa.
    Your public key has been saved in .ssh/id_dsa.pub.
    The key fingerprint is:
    4f:a8:35:74:f7:5e:ac:7e:2d:5f:c5:8d:f3:94:57:51 luc@hoppel
    The key's randomart image is:
    +--[ DSA 1024]----+
    |               .E|
    |                .|
    |        . . .   .|
    |       . o . . ++|
    |        S .   +.O|
    |       o +   . *o|
    |      .   .   o +|
    |             .. +|
    |              .+.|
    +-----------------+

    (py27)luc@hoppel:~$ scp .ssh/id_dsa.pub luc@remote-host-org:~/
    luc@lino-framework.org's password: ***
    id_dsa.pub                                    100%  600     0.6KB/s   00:00    

On the remote host::    
    
    (demo)luc@remote:~$ cat id_dsa.pub >> .ssh/authorized_keys 
    (demo)luc@remote:~$ rm id_dsa.pub
    

(Thanks to http://www.csua.berkeley.edu/~ranga/notes/ssh_nopass.html 
for the cheat sheet)


Sphinx cannot embed stylesheet
--------------------------------

When I run `fab docs` for lino on hoppel, then Sphinx 1.2b1 and
docutils 0.10 say "Cannot embed stylesheet
'...docutils/writers/html4css1/html4css1.css': No such file or
directory.", or more exactly::

    <partial node>:: (ERROR/3) Cannot embed stylesheet '../../../\
    pythonenvs/py27/local/lib/python2.7/site-packages/docutils/writers\
    /html4css1/html4css1.css': No such file or directory.

(Workaround: use docutils 0.9)


Incompatible changes to LOGGING config in Django 1.5
----------------------------------------------------

Ouch, Django 1.5 has changed how to  `Configure logging 
<https://docs.djangoproject.com/en/5.0/topics/logging/#configuring-logging>`_:

    Prior to Django 1.5, the LOGGING setting overwrote the default 
    Django logging configuration. From Django 1.5 forward, the 
    project’s logging configuration is merged with Django’s 
    defaults, hence you can decide if you want to add to, or replace 
    the existing configuration. To completely override the default 
    configuration, set the disable_existing_loggers key to True in 
    the LOGGING dictConfig. Alternatively you can redefine some or 
    all of the loggers.
    

It took me some time to find out that even setting 
`disable_existing_loggers` to `True` doesn't help: Django 
will call my `LOGGING_CONFIG` function twice, once with hard-coded default 
values, then another time with the local settings::

    if self.LOGGING_CONFIG:
        from django.utils.log import DEFAULT_LOGGING
        # First find the logging configuration function ...
        logging_config_path, logging_config_func_name = self.LOGGING_CONFIG.rsplit('.', 1)
        logging_config_module = importlib.import_module(logging_config_path)
        logging_config_func = getattr(logging_config_module, logging_config_func_name)

        logging_config_func(DEFAULT_LOGGING)

        if self.LOGGING:
            # Backwards-compatibility shim for #16288 fix
            compat_patch_logging_config(self.LOGGING)

            # ... then invoke it with the logging settings
            logging_config_func(self.LOGGING)


This is not a nice change! Sigh! 
Opened :djangoticket:`20229` to see what they think about it.

Where is the MergeAction?
-------------------------

The `Merge` action (:mod:`lino.core.merge`) had disappeared.
Because it was added using the `post_analyze` signal.
But (after a change during the last weeks) that's too late, must use pre_analyze. 
Actions defined on the model are "inherited" by each table on that model.
Since this inheriting is done during the analyze phase, our customization 
must happen before.

New method :meth:`lino.core.model.Model.define_action` 
to make this type of customization more bullet-proof.
TODO: define_action should raise an Exception if it is too 
late (because some tables on this model have already been initialized).