[Interest] "Dynamic session lookup supported but failed"

[Thiago Macieira]

On Friday 15 May 2015 09:53:46 René J.V. Bertin wrote:
> Hi,
> 
> I'm seeing this message printed on my terminal when I start Qt5 applications
> under certain conditions, on OS X:
> 
> Dynamic session lookup supported but failed: launchd did not provide a
> socket path, verify that org.freedesktop.dbus-session.plist is loaded!

This means you used QtDBus, which tried to connect to the bus daemon, which 
was compiled with support for launchd but the .plist file wasn't loaded into 
launchd.

> Before I start hunting that string down in the Qt source code: is there a
> way for an application to indicate that it has no business with the DBus or
> any other kind of session lookup? 

No. If you use the D-Bus session bus, it will try to connect. There's no way 
to force it to fail (outside of unit tests).

> If not: does Qt use DBus/"dynamic session
> lookup" behind the scenes to implement certain functionality that the user
> might miss even in a purely standalone application?

Yes. It requires loading the .plist file into launchd.

But since Qt doesn't ship with the daemon, the D-Bus libraries or the .plist 
file, the problem here is that your system *does* have them but didn't configure 
them. Why do you have the D-Bus library somewhere that QtDBus could find it but 
didn't configure it properly?

-- 
Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel Open Source Technology Center