X11 applications in Wayland cannot be run in VSCodium

[NetDwarf]

I just upgraded and X11 (GUI) applications (Avalonia UI specifically) fail to start with the following error:

Unhandled exception. System.Exception: XOpenDisplay failed

The error happens under Wayland, when starting an X11 application in VSCodium. It was introduced with #300 and is fixed by this.

The issue is mostly the assumption in #300 that nosocket=waylaynd is not needed and the wording in the README:

If you have problems to start this flatpak under X11 please run one of these two commands and try again

As it happens under Wayland as well.

[noonsleeper]

Hi @NetDwarf, can you elaborate more about your problem?

[NetDwarf]

Hi @NetDwarf, can you elaborate more about your problem?

I am not sure what to elaborate on. I am in Wayland and compile/open an Avalonia GUI application (X11). This fails since #300 (VSCodium running on Wayland by default instead of X11). It's not unexpected, but the README should be updated accordingly to warn Wayland users.

[noonsleeper]

#300 is about nosocket=x11 that was rejected by the flathub admins not about wayland.

Maybe will be good if you add some steps to reproduce this issue.

[NetDwarf]

I am wrong. It was #298 . To reproduce:

1.) Run Wayland (Gnome in my case)
2.) Download VSCodium
3.) Start an X11 application from within VSCodium

Result: App crashes, because of no display.

Again, this is expected, but the README should reflect that.

[noonsleeper]

@NetDwarf, now is more clear. Can you make that changes on the README and make a PR?

[NetDwarf]

It seems there is actually a direct mitigation without user interaction. Disabling fallback-x11 actually fixes the problem as in #322