Unable to autolaunch a dbus-daemon without a $DISPLAY for X11. NetBeans. Pi as remote host

I am trying to run the following example code using my NetBeans IDE:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dbus/dbus.h>

int main() {
DBusConnection *connection = NULL;
DBusError error;
char buffer[1024];

dbus_error_init(&error);
connection = dbus_bus_get(DBUS_BUS_SESSION, &error);
if (dbus_error_is_set(&error)) {
fprintf(stderr, "%s", error.message);
abort();
}

puts("This is my unique name");
puts(dbus_bus_get_unique_name(connection));
fgets(buffer, sizeof(buffer), stdin);

return 0;
}

From an excellent tutorial:
[DBUS TUTORIAL USING THE LOW-LEVEL API][1]

I have my headless Pi setup for SSH and have installed all the necessary libraries for dbus development.

however, when running the program in Netbeans I receive the following error

Unable to autolaunch a dbus-daemon without a $DISPLAY for X11

`/usr/bin/dbus-launch` terminated abnormally with the following error: Autolaunch error: X11 initialization failed.

note that i have X11 forwarding enabled in my remote host properties on Netbeans

I can see that, if I SSH into the Pi myself and

echo $DISPLAY

this returns nothing, empty.

So far, I have tried:

in /etc/ssh/sshd_config
X11Forwarding yes
X11DisplayOffset 10
X11UseLocalhost no
AllowTcpForwarding yes

did not work.

I tried setting a run environment variable to

DISPLAY export DISPLAY=$HOSTNAME:0.0

0x212d0 "org.freedesktop.DBus.Error.Spawn.ExecFailed"
0x21fe8 "/usr/bin/dbus-launch terminated abnormally with the following error: Autolaunch error: X11 initialization failed.\\n"

didn’t work.

and tried

In /etc/ssh/ssh_config
ForwardX11 yes

did not work.

Is it a case of getting my Pi setup for X11 or configuring my Netbeans environment to run the program with certain parameters?

**update 30 Aug 2017:**

I did a fresh install of Debian and followed Gilles' answer:

[

[To see links please register here]

][2] ...

I can confirm:

in /etc/ssh/sshd_config
X11Forwarding yes
X11DisplayOffset 10

xauth is installed on the remote Pi.

I have installed XQuartz on my client mac. Upon `ssh -X pi@IPaddress`, xquartz opens and if I `echo $DISPLAY` on the remote Pi I get `localhost:12.0` ... the number changes with each terminal.

Currently, if have incorrectly set the project environment in Netbeans with:

DISPLAY=localhost:11.0

_(this is wrong because the number changes with each ssh connection to the remote Pi)._

So when I try to run the program, NetBeans will hang and I can't debug either.

My question at this stage is, how do I set the `$DISPLAY` Environment correctly for NetBeans so that each time it makes an SSH connection to the remote Pi and requests X11 forwarding, it has the correct `$DISPLAY`?


[1]:

[To see links please register here]

[2]:

[To see links please register here]

Autolaunch of dbus-daemon only works when under an X11 session. It is otherwise disabled because there's no way for different applications to establish a common instance of the dbus daemon.

If you want to run a dbus daemon on your pi box independently of X11, you probably should configure it to launch the dbus daemon on startup, and export the bus address in
DBUS_SESSION_BUS_ADDRESS environment variable.

For more info see

[To see links please register here]

If on the other hand you want to use your remote X session, you need to fix your misconfigured X11 forwarding such that the DISPLAY environment variable is set correctly when you ssh into the Pi. See e.g

[To see links please register here]

.

Expanding on **n. 1.8e9-where's-my-share m.**'s answer because this is the top result for Googling "*Unable to autolaunch a dbus-daemon without a $DISPLAY for X11*":

> If you want to run a dbus daemon on your pi box independently of X11, you probably should configure it to launch the dbus daemon on startup, and export the bus address in DBUS_SESSION_BUS_ADDRESS environment variable.

On WSL Ubuntu 20.04:

Make sure dbus service is running:

service dbus status

Export bus address to DBUS_SESSION_BUS_ADDRESS environment variable

export $(dbus-launch)

And this fixed the issue for me