[orca-list] Can't get Orca start in a graphical environment started

[Didier Spaier <didier slint fr>]

Hello,

In Slint gdm speaks, but if I start a desktop session from there orca
doesn't start in the desktop because the connection with at-spi2 through
dbus is refused, possibly still owned by lightdm (but even when
ps -ef |grep at-spi
comes empty, as it is the case  after:
session-setup-script=pkill -u lightdm at-spi
when trying to start I still get this answer:
cut here
didier[~]$ orca

** (orca:2219): WARNING **: Couldn't connect to accessibility bus: Failed to connect to socket 
/tmp/dbus-4zxEfROlmH: Connection refused

** (orca:2219): WARNING **: Couldn't connect to accessibility bus: Failed to connect to socket 
/tmp/dbus-4zxEfROlmH: Connection refused

** (orca:2219): ERROR **: AT-SPI: Couldn't connect to accessibility bus. Is at-spi-bus-launcher running?
Trace/breakpoint trap
didier[~]$
cut here

Currently I have lightdm-1.18.3 and lightdm-gtk-greeter-2.0.3 but I
have also tried lightdm-1.22.0.

There is a similar issue mentioned in this thread:
https://mail.gnome.org/archives/orca-list/2015-December/msg00012.html

I have tried several things, to no avail, including the patch proposed
by Samuel attached to this comment:
https://bugs.launchpad.net/lightdm/+bug/1366534/comments/16
and also writing in lightdm.conf
xserver-share=false

I would be grateful to any pointers to "something that works" which can
be based on any lightdm and lightdm-gtk-greeter versions, possibly with
additional patches, wrapper or other scripts to call from lightdm.conf,
including a properly set up lightdm.conf.
Only restriction: we don't have systemd in Slint, but I doubt that come
into play.

And also to anything that could help a non-coder debugging. 

Greetings,

Didier