Re: [FFADO-devel] FFADO-mixer and python

[Jonathan W. <jw...@ju...>]

Hi Vladimir

On Wed, Mar 11, 2020 at 01:15:13AM +0300, Vladimir Sadovnikov wrote:
> I've noticed that ffado-mixer does not work on my system after installation:
> 
> > ffado-mixer
> > Traceback (most recent call last):
> >   File "/usr/bin/ffado-mixer", line 31, in <module>
> >     from ffado.ffadowindow import *
> >   File "/usr/lib/python3.6/site-packages/ffado/ffadowindow.py", line 35,
> > in <module>
> >     from ffado.dbus_util import *
> >   File "/usr/lib/python3.6/site-packages/ffado/dbus_util.py", line 31, in <module>
> >     from dbus.mainloop.pyqt5 import DBusQtMainLoop
> > ImportError: /usr/lib/python3.6/site-packages/dbus/mainloop/pyqt5.so:
> > undefined symbol: PyModule_Create2

Out of interest, what version of FFADO are you using?  The current
development trunk has some fixes for recent python3/pyqt5/scons
combinations.  It would probably be best to try compiling with this code
to see if any of your issues have been resolved since the latest version was
released.  It won't necessarily address this particular issue (see below)
but it may resolve some of the earlier problems you encountered without a
need for manual intervention.

> In the shebang string I meet:
> 
> > #!/usr/bin/python
> 
> Maybe since you've migrated to python3, ...

We haven't formally migrated to python3.  We still support both python2 and
python3 for various reasons.

> you need to replace it with:
> 
> > #!/usr/bin/python3
> After editing the ffado-mixer script it started to work properly.

Unfortunately there is no agreed convention across distributions as to what
"python" refers to in the case where both python2 and python3 are installed.
As a result, whatever we put in the shebang line is going to be wrong on at
least a few distributions.  Experience to date indicates that the current
arrangement works across the most distributions.  Those which need python3
explicitly stated can trivially make the change during packaging.

Regards
  jonathan