Issue with Wayland

Hello,
I was trying to run Mudlet AppImage without sudo it said: 'Segmentation fault (core dumped)' With sudo it said 'XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root/. No protocol specified. qt.qpa.screen: QXcbConnection: Could not connect to display :0. Could not connect to any X display, however Wayland should also have XWayland, which should serve as backward compatibility for X server or I am mistaken? If you need more info, which I suppose you do, then you need to navigate me in order to obtain necessary information.

[probonopd]

Which exact operating system, version, and desktop environment are you running?
Which exact Mudlet AppImage are you using?

Can you reproduce this on any of the available Linux distribution Live ISOs?

I am running Fedora 27 64-bit with GNOME DE with kernel version 4.15.4-300 on notebook, which is installed on HDD.

I am using 3.7.1 Mudlet AppImage

I tried live ISO of Antergos on my PC and it worked.
I tried live ISO of Fedora 27 on my notebook and it worked. (Same live ISO, which resides on my ntb HDD)
It was needed to run it under sudo, but it worked.
Difference between live ISO output, which works, and Fedora 27 on my HDD is this line:
qt.qpa.screen: QXcbConnection: Could not connect to display :0. Could not connect to any X display

[probonopd]

Please report this issue to the publisher of the Mudlet AppImage.

[vadi2]

As far as I see it's not a problem related to us, or at least I don't know where to start. If the AppImage is working on certain distributions and not on others, it would seem to be a distribution problem, not a software one...

[probonopd]

Well, since AppImage is just a self-mounting filesystem that executes whatever is inside the AppImage, I think we need to look for the issue either in the application, the dependencies it uses (e.g., Qt), and/or the system that was used to deploy those into the AppImage (e.g., linuxdeployqt).

I tried to install Antergos on my notebook and tried to launch Mudlet. It was successful. My guess is that some package within QT is not installed by default in Fedora and is not included in Mudlet AppImage, since mentioned variables are set on same value. Probably something like with Texlive. You install it as a whole, but if you need something specific, you need to install that separately (texlive-cjk) or from RPMFusion (texlive-babel-czech).

[probonopd]

I tried to install Antergos on my notebook and tried to launch Mudlet. It was successful.

Thanks for testing. Interesting. Is Antergos using Wayland or Xorg or Xorg-on-Wayland?

My guess is that some package within QT is not installed by default in Fedora and is not included in Mudlet AppImage

The Qt bundled inside an AppImage should never attempt to use Qt modules from the system, since this will lead to crashes due to version mismatches.

[pdfkungfoo]

@vadi2:

'If the AppImage is working on certain distributions and not on others, it would seem to be a distribution problem, not a software one...'

Well, you can easily build an "AppImage" on a very current and bleeding-edge system, which will NOT run on MOST systems. While it may technically be an AppImage, it would not by one by spirit... It may not be a problem of the payload software itself, but a problem with the specific way the AppImage was built.

(@vadi2: I wrote my above comment without knowing anything about Mudlet or its AppImage building environment, so please don't take this as a personal reference to YOU or YOUR work. It's just a comment about that specific statement of yours, which seems to be too general to justify the logic of its conclusion...)

Antergos is arch-based distribution with LightDM manager. Somehow it was running under x11 (xorg), when it should be running under wayland, so I installed gdm and xorg-server-xwayland as a dependency and gone through GDM. It's running under wayland properly now. Tested both x11 (xorg) and wayland sessions with Mudlet. Both seem to be working with Mudlet. I am running GNOME v3.26.1-2.

[vadi2]

Mudlet's AppImage is built on Travis's standard trusty image, build log for the image in question is https://travis-ci.org/Mudlet/Mudlet/jobs/320754399.

[sudo-give-me-coffee]

Wayland is a joke, most programs in all distribution formats do not run and developers do not listen to users

With these steps you can run your application (it worked for me):

• Fix "XDG_RUNTIME_DIR":

xdg-user-dirs-update
sudo su
cd ~
xdg-user-dirs-update

• Fix "Could not connect to display :0"

Just install XWayland

---

In some cases before starting application is needed run:

export "DISPLAY=:0"

[probonopd]

@sudo-give-me-coffee thanks for your help here. Is it fair to say this is an issue of the distribution, as the distribution should do the xdg-user-dirs-updateand the export "DISPLAY=:0"?

[sudo-give-me-coffee]

@probonopd So,

The xdg-user-dirs-update yes, but export "DISPLAY =: 0" no, this should be done by Wayland whenever running an application that depends on X.org (XWayland),

$ XDG_RUNTIME_DIR I don't know what happens and the reason for xdg-user-dirs fix it in some cases, because this is a necessary environment variable for multiple applications, and normally (outside of wayland) is required to follow these steps to fix:

Xvfb :0 -screen 0 [screen resolution]x[monitor frequency] +extension GLX -nolisten tcp -dpi 96
export DISPLAY=:0
xhost +SI:localuser:root
sudo whatever...
xhost -SI:localuser:root
xhost

So i think that if xdg-user-dirs-update fix, there isn't issue of the distribution

@Omaj7 This #664 (comment) fix?

[probonopd]

So it loos we can close this issue here, do you agree? Or do you think AppImageKit needs to change something?