You can have - or _ but no dots in linux environment variable names. Depending on your environment you might also get in trouble with the name not being in CAPS.
Setting engine-specific variables for Slate has to be done differently if that’s what you’re after.
tl;dr: solved wrong dropdowns placement and tooltips focus stealing in X11 by running the Editor via xwayland-satellite. Started the xwayland-satellite in one terminal window and DISPLAY=:1 SDL_VIDEODRIVER=x11 path/to/Binaries/Linux/UnrealEditor in another.
Another option was to switch to Gnome (gnome-shell / gnome-session), but I did not want to (I’m using Sway).
More details
Editor’s Wayland mode is still not usable for me: before 5.7.1 (or maybe 5.7.0?) it crashed soon after start. In 5.7.1 and 5.7.2 it runs, but all dropdowns are placed in the center of the screen, do not respond to clicks and tooltips are stealing focus.
So I have always run the editor with SDL_VIDEODRIVER=x11.
In the recent updates (5.7.2 and 5.71, not sure about 5.7.0) the inconsistency was fixed, and tooltips-dropdowns started behave the same way even with X11: center of the screen, to clicks, focus stealing.
Turned out, the Editor still works OK under Gnome Shell (even the tooltips, in the x11 mode), but I prefer Sway and I did not want to run both WMs and switch back and forth.
Turned out, the Editor also works OK (almost) via xwayland-satellite:
start xwayland-satellite;
check the logs for port number, something like Connected to Xwayland on :1 (for me it was :1 since :0 was was occupied by Xwayland);
run the editor with DISPLAY=<port> SDL_VIDEODRIVER=x11.
Turned out, the dropdowns also work correctly when Editor is run via labwc, but it doesn’t solve tooltips problem.
Have been quietly watching since this is still prerelease but at a “.2” release and still not fixing basic UI issues on a pretty common platform that used to work fine in 5.6.1 is confusing. I’m not interested in x11 work-arounds so will wait until Epic addresses this (so I know I can trust the things I create will also work without workaround).
I can confirm these issues still exist on 5.7.0, 5.7.1, 5.7.2 on Fedora 43…. So I continue to work in 5.6.1 (which works fine so it CAN work).
I hope this gets addressed… I would like to migrate our projects to 5.7.
It probably won’t be fixed for a long time is my guess, I built ue5-main from source earlier this week and it has all the same issues. Considering this has been known since at least June/July of last year and ue5-main is the main development branch for Unreal, and there’s been no progress… well…
I was using Debian 13 with Xfce and it was buggy. I tested Debian 13 with Gnome using Wayland and then with X11, and everything worked normally. It seems that support only covers Debian-based distributions with Gnome.
For me Unreal 6.7.3 works on Kubuntu 25.10 with SDL_VIDEODRIVER=x11 environment variable quite fine. No other focus hack needed. Also checkboxes buttons are working inside notifications.
agree. a rollback would be great then they can add when its ready. a lots of ppl swapping to linux these days. there are many workarounds but still having annoying stuff.
Fedora 43 KDE 6.6.0 Wayland, Unreal 5.7.3
Absolutely quite broken.. I tried all the workarounds mentioned in this thread, and it’s close, but not good enough..
5.6.1 has been working great, so what went wrong with 5.7 ?