:date: 2019-09-19

============================
Thursday, September 19, 2019
============================

Miscellaneous
=============

I subtle change in the Lino core in order to optimize testing:
:meth:`lino.utils.diag.Analyzer.show_window_fields` no longer shows dummy
fields. Because it was irritating to see the
:attr:`lino_xl.lib.cv.LanguageKnowledge.entry_date` field appear in the doctests
for :ref:`welfare` where they don't want to have this field.

Version mismatch: this is the 'cffi' package version 1.12.3
===========================================================

Back to work on :ticket:`3095`, continued after :doc:`0918` where I stopped
here::

  [Wed Sep 18 15:37:21.750588 2019] [wsgi:error] [pid 3357:tid 140319710512896]
  Exception: Version mismatch: this is the 'cffi'
  package version 1.12.3, located in
  '/usr/local/lino/lino_local/prod/env/lib/python3.7/site-packages/cffi/api.py'.
  When we import the top-level '_cffi_backend' extension module, we get version
  1.12.2, located in
  '/usr/lib/python3/dist-packages/_cffi_backend.cpython-37m-x86_64-linux-gnu.so'.
  The two versions should be equal; check your installation.

Looks as if the cffi in the site's environment is finding the cffi of the
server-wide environment.

But the server-wide Python does not seem to have cffi installed::

  # python3
  Python 3.7.3 (default, Apr  3 2019, 05:39:12)
  [GCC 8.3.0] on linux
  Type "help", "copyright", "credits" or "license" for more information.
  >>> import cffi
  Traceback (most recent call last):
    File "<stdin>", line 1, in <module>
  ModuleNotFoundError: No module named 'cffi'
  >>>

Why then does it have a file
:file:`_cffi_backend.cpython-37m-x86_64-linux-gnu.so`?

Why do I have that cffi package installed at all?  What does it do? Which module
requires it?

What is the difference between :file:`/usr/lib/python3/dist-packages` and
:file:`/usr/local/lib/python3/dist-packages`?

Ouch, I just read `here
<https://stackoverflow.com/questions/54234344/the-reason-cause-different-location-of-python-packages>`__
that "(note: do not use sudo pip, which can cause problems)." That's what I
currently instruct to do in :ref:`getlino.install.contrib`.

And also: :file:`/usr/lib` is for modules installed by the system with the
package manager (e.g. with :cmd:`sudo apt-get python-numpy`) while
:file:`/usr/local/lib` is for modules that you installed yourself system-wide
(e.g. with :cmd:`sudo pip install numpy`

After reading `this
<https://stackoverflow.com/questions/43325110/exception-version-mismatchcffi>`__,
I tried to install `python3-cffi` as a system package::

  $ sudo apt-get install python3-cffi
  ...
  The following NEW packages will be installed:
    python3-cffi python3-ply python3-pycparser
  ...

And whoops, the problem is gone!  But don't ask me why...

TODO: review :ref:`getlino.install` to not use "sudo pip3", e.g. by always using
a shared env which contains at least getlino.

Install eidreader handler on tups
=================================

I needed to install a custom url handler for `beid://` links, so I used the
documentation about :ref:`eidreader.install` and reviewed it en passant.


Run the migration script
========================

I ran the migration script prod2preview for weleup because I had an
operationdatabase error because LanguageKnowledge.use_certificate had not yet
been created. Nothing special.


Amici removes participants of my meeting
========================================

I started working on :ticket:`3210` (Amici removes participants of my meeting).
Continued :doc:`0920`.