Arch Linux User Repository

I currently recommend building 5.6.1 over any version of 5.7 as this branch holds a notoriously broken Vulkan RHI implementation, leading to unexpected VK_ERROR_DEVICE_LOST crashes due to a race condition. Just modify pkgver on your end with the aformentioned version and you should be good to go.

A discussion here goes into detail about the issue, but no proper fix is currently planned by Epic.

A merge request has also been proposed here, but the fix itself was in the end apparently not very effective.

The Vulkan crashes were recently fixed in 5.8, check here.

You can still try on your own if you still insist on using 5.7.x, especially if you're motivated to fix this issue on your side. If so, don't hesitate to send a comment with your patch, I could add you as a contributor to this package if you are interested.

Reducing crashes can be done by doing the following two steps:

• Add these lines in DefaultEngine.ini (either in your project or the editor's installation dir, /opt/unreal-engine/Engine/Config/DefaultEngine.ini by default)

[/Script/Engine.RendererSettings]
r.Vulkan.WaitForIdleOnSubmit=1
r.Vulkan.EnablePipelineLRUCache=1

• Add these two lines as well in the editor's ConsoleVariables.ini file (/opt/unreal-engine/Engine/Config/ConsoleVariables.ini by default):

Slate.EnableToolTips=0
Slate.bAllowNotifications=0

Do note that using Wayland for Unreal Engine is currently not recommended as half of the UI interactions are broken. This is due to a recent upgrade to SDL3 which defaults the use of Wayland protocols over X11 when launching on a Wayland-based session.

You can work around this (or at least improve your experience) while still being on Wayland by opening a separate Xorg windowed server:

export DISPLAY=:1

Xwayland ${DISPLAY} -decorate -geometry 1920x1080 &
kwin_x11 &
unreal-engine 

You can, of course, replace kwin_x11 with your desktop environment window manager (GNOME is mutter for example).

@juancarlospaco this is easily done on your own system, not in a PKGBUILD, given that building packages runs as root:

sudo groupadd unrealengine-users
sudo usermod -aG unrealengine-users (your-username)
sudo chown -R root:unrealengine-users /opt/unreal-engine
sudo chmod -R 775 /opt/unreal-engine

Permission issues like this are already mentioned on the UE Arch wiki page: https://wiki.archlinux.org/title/Unreal_Engine_4#Installing_from_the_AUR

This is a user system problem; I already did what I could without needing users to do the above by giving the 777 permissions. If it still gives you trouble, you'll have to use the example to solve it or change the install location to somewhere you have user permissions by default (as I cannot do this for you).

@OdinVex: sorry if it's me being dumb again, but... I have the same error:

$ makepkg -s --skipchecksums
==> Making package: unreal-engine 5.2.1-0 (Fri Jun 23 23:17:59 2023)
==> Checking runtime dependencies...
==> Checking buildtime dependencies...
==> Retrieving sources...
  -> Found unreal-engine-5.sh
  -> Found com.unrealengine.UE4Editor.desktop
  -> Found use_system_clang.patch
  -> Found unreal-engine-5-pacman-cache.hook
  -> Found ue5editor.svg
==> WARNING: Skipping verification of source file checksums.
==> Extracting sources...
==> Starting prepare()...
==> ERROR: A failure occurred in prepare().
    Aborting...

PKGBUILD: http://ix.io/4yVM

@k1gen Upload your PKGBUILD, sounds like you forgot a line then because nothing should be gitting. BUT the one ICON is fetched from GitHub.

Overly obvious clarification:

build() {
  cd "${pkgname}" || return

  #temporarily disable building
  return
...

prepare() {
  cd "${pkgname}" || return

  #temporarily disable building
  return
...

@OdinVex: understood, did that. makepkg -s --skipchecksums just started git cloning stuff in my 257Gb src dir :| here's my PKGBUILD: http://ix.io/4yVH

@k1gen Don't forget that prepare() needs to end up in the $pkgname dir, so it should be exactly like build()'s intro with cd "${pkgname}" || return as well.

thanks, didn't notice that for some reason. with return just after prepare() I have this error:

==> ERROR: A failure occurred in prepare().
    Aborting...

@k1gen You forgot to add a return for prepare() too, it should be the first line...that way it isn't touched. Do the same to prepare() that you did for build(). :)

@OdinVex: for the last twelve hours everything was building, as I started the second build before Neko-san fixed the icon issue. now that everything built fine with old PKGBUILD, I edited it to include icon fix and add return in build(). can you please check the PKGBUILD, does it look fine? I'm worried about rm -rf "$(pkgname)" on line 150: http://ix.io/4yVF

@k1gen Bit confused by what you mean about second build finishing and 'now try to edit'. o_O You're welcome.

@OdinVex: thank you very much, again. I will now try to edit the PKGBUILD, as the second build just finished

@k1gen When the next version comes out, it's safe to just uninstall UE and clean the cache, then install normally. This was just a one-time oof. ;) In the future, it is pretty much safe to always use yay, but for big packages or things that take a long time, just clone the AUR (and subscribe for version updates) and use makepkg -si. By the way, when you use makepkg for this stuff, yay detects that too and will appropriately see it, so there isn't conflict. (But again, it currently thinks your build is old simply because of the commit pushes. Just wait to mass update with yay until after unreal-engine gets a version bump. :))