Arch Linux User Repository

@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).

Will update to 5.0 when it is released.

@Neko-san for UE5 I used your PKGBUILD, seems the problem is in something else...So, in your build there is no such error?

@CtHx o_o

Use the PKGBUILD I already provided below. There's significant differences between UE4 and 5 and just changing the version at the top is not how that works.

@Neko-san I did only small modifications (changed to the latest version: 4.27.2 and 5.0.1, for 5x version added DOTNET_SYSTEM_GLOBALIZATION_INVARIANT=1 in prepare() section). Fixing .SRCINFO didn't solve my problem. For UE5 I have similar errror:

****** [3/10] Compile UnrealEditor Linux

Reading local file list from /mnt/sdb/xz1/builds/unreal-engine/src/unreal-engine/Engine/Saved/BuildGraph/Compile UnrealHeaderTool Linux/Tag-Compile UnrealHeaderTool Linux.xml
Reading local file list from /mnt/sdb/xz1/builds/unreal-engine/src/unreal-engine/Engine/Saved/BuildGraph/Update Version Files/Tag-Update Version Files.xml
Reading shared manifest from /mnt/sdb/xz1/builds/unreal-engine/src/unreal-engine/Engine/Saved/BuildGraph/Compile UnrealHeaderTool Linux/Manifest.xml
Running: /mnt/sdb/xz1/builds/unreal-engine/src/unreal-engine/Engine/Binaries/DotNET/UnrealBuildTool/UnrealBuildTool UnrealEditor Linux DebugGame  -NoUBTMakefiles -nobuilduht -precompile -allmodules  -Manifest=/mnt/sdb/xz1/builds/unreal-engine/src/unreal-engine/Engine/Intermediate/Build/Manifest.xml -NoHotReload -log="/home/user/Library/Logs/Unreal Engine/LocalBuildLogs/UBT-UnrealEditor-Linux-DebugGame.txt"
Log file: /home/user/Library/Logs/Unreal Engine/LocalBuildLogs/UBT-UnrealEditor-Linux-DebugGame.txt
Using 'git status' to determine working set for adaptive non-unity build (/mnt/sdb/xz1/builds/unreal-engine/src/unreal-engine).
Parsing headers for UnrealEditor
  Running UnrealHeaderTool UnrealEditor "/mnt/sdb/xz1/builds/unreal-engine/src/unreal-engine/Engine/Intermediate/Build/Linux/B4D820EA/UnrealEditor/DebugGame/UnrealEditor.uhtmanifest" -LogCmds="loginit warning, logexit warning, logdatabase error" -Unattended -WarningsAsErrors -abslog="/home/user/Library/Logs/Unreal Engine/LocalBuildLogs/UHT-UnrealEditor-Linux-DebugGame.txt"
Took 20.088337s to run UnrealBuildTool, ExitCode=3
UnrealBuildTool failed. See log for more details. (/home/user/Library/Logs/Unreal Engine/LocalBuildLogs/UBT-UnrealEditor-Linux-DebugGame.txt)
AutomationTool executed for 0h 6m 9s
AutomationTool exiting with ExitCode=3 (Error_UnknownCommand)
RunUAT ERROR: AutomationTool was unable to run successfully. Exited with code: 3

UBT-UnrealEditor-Linux-DebugGame.txt:

...
UnrealHeaderTool needs to run because no generated code directory was found for module CoreUObject
Parsing headers for UnrealEditor
  Running UnrealHeaderTool UnrealEditor "/mnt/sdb/xz1/builds/unreal-engine/src/unreal-engine/Engine/Intermediate/Build/Linux/B4D820EA/UnrealEditor/DebugGame/UnrealEditor.uhtmanifest" -LogCmds="loginit warning, logexit warning, logdatabase error" -Unattended -WarningsAsErrors -abslog="/home/user/Library/Logs/Unreal Engine/LocalBuildLogs/UHT-UnrealEditor-Linux-DebugGame.txt"
CompilationResultException: Error: CrashOrAssert
   at UnrealBuildTool.ExternalExecution.ExecuteHeaderToolIfNecessary(BuildConfiguration BuildConfiguration, FileReference ProjectFile, TargetMakefile Makefile, String TargetName, ISourceFileWorkingSet WorkingSet) in /mnt/sdb/xz1/builds/unreal-engine/src/unreal-engine/Engine/Source/Programs/UnrealBuildTool/System/ExternalExecution.cs:line 1275
   at UnrealBuildTool.UEBuildTarget.Build(BuildConfiguration BuildConfiguration, ISourceFileWorkingSet WorkingSet, TargetDescriptor TargetDescriptor) in /mnt/sdb/xz1/builds/unreal-engine/src/unreal-engine/Engine/Source/Programs/UnrealBuildTool/Configuration/UEBuildTarget.cs:line 1773
   at UnrealBuildTool.BuildMode.CreateMakefile(BuildConfiguration BuildConfiguration, TargetDescriptor TargetDescriptor, ISourceFileWorkingSet WorkingSet) in /mnt/sdb/xz1/builds/unreal-engine/src/unreal-engine/Engine/Source/Programs/UnrealBuildTool/Modes/BuildMode.cs:line 742
   at UnrealBuildTool.BuildMode.Build(List`1 TargetDescriptors, BuildConfiguration BuildConfiguration, ISourceFileWorkingSet WorkingSet, BuildOptions Options, FileReference WriteOutdatedActionsFile, Boolean bSkipPreBuildTargets) in /mnt/sdb/xz1/builds/unreal-engine/src/unreal-engine/Engine/Source/Programs/UnrealBuildTool/Modes/BuildMode.cs:line 267
   at UnrealBuildTool.BuildMode.Execute(CommandLineArguments Arguments) in /mnt/sdb/xz1/builds/unreal-engine/src/unreal-engine/Engine/Source/Programs/UnrealBuildTool/Modes/BuildMode.cs:line 237
   at UnrealBuildTool.UnrealBuildTool.Main(String[] ArgumentsArray) in /mnt/sdb/xz1/builds/unreal-engine/src/unreal-engine/Engine/Source/Programs/UnrealBuildTool/UnrealBuildTool.cs:line 593
WriteFileIfChanged() wrote 0 changed files of 0 requested writes.

@CtHx one of the command used for the "running mono" line (one of the dash arguments probably) is considered invalid. Did you modify the PKGBUILD at all?

Also, be sure to delete the hidden .SRCINFO file if you haven't and generate a new one prior to building: makepkg --printsrcinfo >> .SRCINFO

I have this compilation error (for UE4 and 5):

****** [3/10] Compile UE4Editor Linux

Reading local file list from /mnt/sdb/xz1/builds/unreal-engine/src/unreal-engine/Engine/Saved/BuildGraph/Compile UnrealHeaderTool Linux/Tag-Compile UnrealHeaderTool Linux.xml
Reading local file list from /mnt/sdb/xz1/builds/unreal-engine/src/unreal-engine/Engine/Saved/BuildGraph/Update Version Files/Tag-Update Version Files.xml
Reading shared manifest from /mnt/sdb/xz1/builds/unreal-engine/src/unreal-engine/Engine/Saved/BuildGraph/Compile UnrealHeaderTool Linux/Manifest.xml
Running: mono "/mnt/sdb/xz1/builds/unreal-engine/src/unreal-engine/Engine/Binaries/DotNET/UnrealBuildTool.exe" UE4Editor Linux DebugGame  -NoUBTMakefiles -nobuilduht -precompile -allmodules -Manifest=/mnt/sdb/xz1/builds/unreal-engine/src/unreal-engine/Engine/Intermediate/Build/Manifest.xml -NoHotReload -log="/home/user/Library/Logs/Unreal Engine/LocalBuildLogs/UBT-UE4Editor-Linux-DebugGame.txt"
  Using 'git status' to determine working set for adaptive non-unity build (/mnt/sdb/xz1/builds/unreal-engine/src/unreal-engine).
  Parsing headers for UE4Editor
    Running UnrealHeaderTool UE4Editor "/mnt/sdb/xz1/builds/unreal-engine/src/unreal-engine/Engine/Intermediate/Build/Linux/B4D820EA/UE4Editor/DebugGame/UE4Editor.uhtmanifest" -LogCmds="loginit warning, logexit warning, logdatabase error" -Unattended -WarningsAsErrors -abslog="/home/user/Library/Logs/Unreal Engine/LocalBuildLogs/UHT-UE4Editor-Linux-DebugGame.txt"
Took 5,047105s to run mono, ExitCode=3
UnrealBuildTool failed. See log for more details. (/home/user/Library/Logs/Unreal Engine/LocalBuildLogs/UBT-UE4Editor-Linux-DebugGame.txt)
AutomationTool exiting with ExitCode=3 (Error_UnknownCommand)
RunUAT ERROR: AutomationTool was unable to run successfully.

What am I doing wrong?

5.0.1 was released. Can we get an update please?

@joshtau @Neko-san You can work around the ICU issue by setting DOTNET_SYSTEM_GLOBALIZATION_INVARIANT=1.

@chovy, 5.0 is a buggy pile, seriously wrecks almost all v4 projects and v5 has issues on its own. Might be best to wait for a 5.1 or 5.2.

@joshtau icu recently had an update, so this is probably why the script is complaining; I wouldn't personally be able to give an answer for why this particular issue occurs though :/

The only advice I can give for this, until someone finds a more concrete solution or Epic supports the newer versions, is to downgrade and hold the icu package(s) prior to building

Thanks nekosan, I can compile this manually but using the script throws this error:

Process terminated. Couldn't find a valid ICU package installed on the system. Set the configuration flag System.Globalization.Invariant to true if you want to run with no globalization support.

Not sure why, as icu and friends are installed.