[LAD] Failed to connect to session bus for device reservation

[Len Ovens]

On Wed, 15 Feb 2017, Ralf Mattes wrote:

>
> Am Dienstag, 14. Februar 2017 18:58 CET, Len Ovens <len at ovenwerks.net> schrieb:
>>>
>>> No X11 -> No DBus
>>
>> Not true. I have done
>> dbus-launch screen
>> and used screen as my text only session manager with success. jack_control
>> was able to start jackdbus, pulse was able to run and bridge to jack on a
>> headless system. (it has been a while, I stopped because the system I was
>> using was too memory strapped) Any of the terminals in the same screen
>> instance will be able to communicate with any other.
>>
>> So it is possible.
>
> Yes, it is possible. But it also shows how little is known about dbus in the
> audio comunity (lack of documentation/quality of doxumentaion?).
> A naive (?) 'man jackd' won't even mention dbus. Want more ridicule?
> 'man jackdbus' :
> No manual entry for jackdbus
> See 'man 7 undocumented' for help when manual pages are not available.

I can add more too. The tool for starting jackdbus, jack_control, has no 
docs. No man page, -h, --help do not work. running jack_control with no 
command gives a usage screen... and as it is a python script, the script 
itself is probably the best documentation there is (and still nor great).

> >  It does mean learning more about your system...
>
> Hmm - did you? You suggest using dbus-launch even so the manpage of that program
> explicitly says "To start a D-Bus session within a text-mode session, do not use dbus-launch"
> and point to dbus-run-session ...

Just enough to get things to work (and the experiment failed because I 
had only 0.3G ram, not because of dbus). However, having read the two man 
pages, I would still use dbus-launch with a text session manager like screen 
where I want to share one instance of dbus with a number of processes.

Certainly I am no great sysadmin. I could also use more learning time on 
my system, but in general I have a system to use it, not learn about it's 
inner workings... So I learn only enough to get things to work, I copy 
lots of stuff others have done and ask questions.

One of the biggest problems in linux audio is old information, linux and 
the surrounding OS has changed. I should actually try my test setup again 
with more memory and try both commands as I have such a box sitting here.

--
Len Ovens
www.ovenwerks.net