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.

@urbenlegend Just make a group and make your account a member of it.

I'll have to look into adjusting those paths. I think the engine places a few there while being built. Won't be able to edit those. Though, I can definitely do one of them.

@zerophase The build and install went well, but there's quite a few permissions issues in /opt/unreal-engine

drwxrwx--- 13 root root 4096 May  5 19:06 Engine/
drwxr-xr-x  2 root root 4096 May  5 19:09 FeaturePacks/
-rwxrwx---  1 root root  736 May  5 18:00 GenerateProjectFiles.sh*
drwxr-xr-x  4 root root 4096 May  5 19:09 Samples/
-rwxrwx---  1 root root 1690 May  5 18:00 Setup.sh*
drwxr-xr-x 43 root root 4096 May  5 19:09 Templates/

As you can see, quite a few files and directories are inaccessible to normal users. The /usr/share/applications/com.unrealengine.UE4Editor.desktop shortcut also has the same issue.

In addition to that, I also noticed that user shortcuts get created in ~/.local/share/applications, but those point to the AUR build directory instead of /opt/unreal-engine.

When I fix the permissions so that things in /opt/unreal-engine are readable, I then get a dialog that pops up saying "Local data cache path (../../../Engine/DerivedDataCache) is unavailable so cache will be disabled. Does it require write access to /opt/unreal-engine for normal users?

@zerophase Works perfectly now! I had noticed the msbuild warning before, but since it proceeded after that step I never thought that it was necessary. Thanks for the quick fix!

@urbenlegend Think it's from msbuild not being installed. Added it as a dependency. Try now.

Which mono package do you have installed?

@zerophase Here are the complete logs

:: Downloading PKGBUILDs...
 PKGBUILDs up to date
 nothing new to review
fetching devel info...
==> Making package: unreal-engine 4.26.2-2 (Wed 05 May 2021 10:55:55 AM PDT)
==> Retrieving sources...
  -> Found com.unrealengine.UE4Editor.desktop
  -> Found clang_11.patch
  -> Found PackageWithSystemCompiler.patch
  -> Found ccache_executor.patch
  -> Found compile_and_regenerate.patch
  -> Found processor_multiplier.patch
  -> Found BuildConfiguration.xml
==> Validating source files with sha256sums...
    com.unrealengine.UE4Editor.desktop ... Passed
    clang_11.patch ... Passed
    PackageWithSystemCompiler.patch ... Passed
    ccache_executor.patch ... Passed
    compile_and_regenerate.patch ... Passed
    processor_multiplier.patch ... Passed
    BuildConfiguration.xml ... Passed
==> Making package: unreal-engine 4.26.2-2 (Wed 05 May 2021 10:55:55 AM PDT)
==> Checking runtime dependencies...
==> Checking buildtime dependencies...
==> Retrieving sources...
  -> Found com.unrealengine.UE4Editor.desktop
  -> Found clang_11.patch
  -> Found PackageWithSystemCompiler.patch
  -> Found ccache_executor.patch
  -> Found compile_and_regenerate.patch
  -> Found processor_multiplier.patch
  -> Found BuildConfiguration.xml
==> Validating source files with sha256sums...
    com.unrealengine.UE4Editor.desktop ... Passed
    clang_11.patch ... Passed
    PackageWithSystemCompiler.patch ... Passed
    ccache_executor.patch ... Passed
    compile_and_regenerate.patch ... Passed
    processor_multiplier.patch ... Passed
    BuildConfiguration.xml ... Passed
==> Removing existing $srcdir/ directory...
==> Extracting sources...
==> Starting prepare()...
Cloning into 'unreal-engine'...
remote: Enumerating objects: 111586, done.
remote: Counting objects: 100% (111586/111586), done.
remote: Compressing objects: 100% (83465/83465), done.
remote: Total 111586 (delta 26854), reused 91685 (delta 25019), pack-reused 0
Receiving objects: 100% (111586/111586), 236.45 MiB | 9.71 MiB/s, done.
Resolving deltas: 100% (26854/26854), done.
Note: switching to 'c3caf7b6bf12ae4c8e09b606f10a09776b4d1f38'.

You are in 'detached HEAD' state. You can look around, make experimental
changes and commit them, and you can discard any commits you make in this
state without impacting any branches by switching back to a branch.

If you want to create a new branch to retain commits you create, you may
do so (now or later) by using -c with the switch command. Example:

  git switch -c <new-branch-name>

Or undo this operation with:

  git switch -

Turn off this advice by setting config variable advice.detachedHead to false

Updating files: 100% (137999/137999), done.
patching file Engine/Source/Editor/UnrealEd/Public/Layers/LayersSubsystem.h
patching file Engine/Source/Programs/UnrealBuildTool/Platform/Linux/LinuxToolChain.cs
patching file Engine/Source/Runtime/Core/Public/GenericPlatform/GenericPlatformCriticalSection.h
patching file Engine/Source/Runtime/Core/Public/HAL/PThreadCriticalSection.h
patching file Engine/Source/Runtime/Core/Public/UObject/WeakObjectPtrTemplates.h
patching file Engine/Source/Runtime/Foliage/Private/ProceduralFoliageSpawner.cpp
Hunk #1 succeeded at 100 (offset 20 lines).
patching file Engine/Source/ThirdParty/FBX/2020.1.1/include/fbxsdk/scene/geometry/fbxlayer.h
patching file Engine/Source/Developer/TargetPlatform/Private/TargetPlatformManagerModule.cpp
Hunk #1 succeeded at 1035 (offset 3 lines).
patching file Engine/Source/Editor/MainFrame/Private/Frame/MainFrameActions.cpp
patching file Engine/Source/Programs/AutomationTool/AutomationUtils/BuildCommand.cs
patching file Engine/Source/Programs/AutomationTool/AutomationUtils/CommandUtils.cs
patching file Engine/Source/Programs/AutomationTool/Scripts/BuildCookRun.Automation.cs
patching file Engine/Source/Programs/AutomationTool/Scripts/BuildProjectCommand.Automation.cs
patching file Engine/Source/Developer/DesktopPlatform/Private/DesktopPlatformBase.cpp
patching file Engine/Source/Developer/DesktopPlatform/Private/DesktopPlatformBase.h
patching file Engine/Source/Developer/HotReload/Private/HotReload.cpp
patching file Engine/Source/Programs/AutomationTool/Scripts/BuildTarget.Automation.cs
patching file Engine/Source/Programs/AutomationTool/Scripts/SyncProject.Automation.cs
patching file Engine/Source/Runtime/Core/Private/Misc/Paths.cpp
patching file Engine/Source/Runtime/Core/Public/Misc/Paths.h
patching file Engine/Source/Programs/UnrealBuildTool/Configuration/BuildConfiguration.cs
patching file Engine/Source/Programs/UnrealBuildTool/Executors/Experimental/CCache.cs
patching file Engine/Source/Programs/UnrealBuildTool/Executors/LocalExecutor.cs
patching file Engine/Source/Programs/UnrealBuildTool/System/ActionGraph.cs
patching file Engine/Source/Programs/UnrealBuildTool/ToolChain/UEToolChain.cs
patching file Engine/Source/Programs/UnrealBuildTool/UnrealBuildTool.csproj
Hunk #1 succeeded at 141 (offset -1 lines).
patching file Engine/Source/Programs/UnrealBuildTool/Executors/LocalExecutor.cs
Cloning into 'QtCreatorSourceCodeAccess'...
remote: Enumerating objects: 18, done.
remote: Counting objects: 100% (18/18), done.
remote: Compressing objects: 100% (17/17), done.
remote: Total 18 (delta 5), reused 8 (delta 0), pack-reused 0
Receiving objects: 100% (18/18), 14.04 KiB | 14.04 MiB/s, done.
Resolving deltas: 100% (5/5), done.
Registering git hooks... (this will override existing ones!)
Fixing inconsistent case in filenames.
which: no msbuild in (/home/username/kde/src/kdesrc-build:/home/username/bin:/home/username/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/bin:/var/lib/flatpak/exports/bin:/usr/lib/jvm/default/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl)
Running system mono, version: 6
Checking dependencies...
Updating dependencies: 100% (63485/63485), 11782.7/11782.7 MiB | 15.59 MiB/s, done.
Result: 0
Register the engine installation...

Target arch set to: x86_64-unknown-linux-gnu
Building ThirdParty libraries

If you don't see SUCCESS message in the end, then building did not finish properly.
In that case, take a look into /home/username/.cache/paru/clone/unreal-engine/src/unreal-engine/Engine/Build/BatchFiles/Linux/BuildThirdParty.log for details.

No third party libs needed to be built locally

**********  SUCCESS ****************
Setup successful.
Attempting to set up UE4 pretty printers for gdb (existing UE4Printers.py, if any, will be overwritten)...
        updated UE4Printers.py
        found necessary entries in ~/.gdbinit file, not changing it.

Setting up Unreal Engine 4 project files...

Fixing inconsistent case in filenames.
which: no msbuild in (/home/username/kde/src/kdesrc-build:/home/username/bin:/home/username/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/bin:/var/lib/flatpak/exports/bin:/usr/lib/jvm/default/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl)
Running system mono, version: 6
Executors/LocalExecutor.cs(358,20): warning CS0219: The variable 'ActionProcess' is assigned but its value is never used                                                                                
WARNING: Project file formats specified via the command line will be ignored when generating
         project files from the editor and other engine tools.                                      

         Consider setting your desired IDE from the editor preferences window, or modify your       
         BuildConfiguration.xml file with:                                                          

         <?xml version="1.0" encoding="utf-8" ?>                                                    
         <Configuration xmlns="https://www.unrealengine.com/BuildConfiguration">                    
           <ProjectFileGenerator>                                                                   
             <Format>Make</Format>                                                                  
           </ProjectFileGenerator>                                                                  
         </Configuration>                                                                           
ERROR: Unhandled exception: System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.Security.SecurityException: No access to the given key ---> System.UnauthorizedAccessException: Access to the path '/etc/mono/registry/LocalMachine' is denied. ---> System.IO.IOException: Permission denied                                                    
          --- End of inner exception stack trace ---                                                
         at System.IO.FileSystem.CreateDirectory (System.String fullPath) [0x00191] in <efe941bb62534dc3a62ceb1a818964a0>:0                                                                             
         at System.IO.Directory.CreateDirectory (System.String path) [0x0002c] in <efe941bb62534dc3a62ceb1a818964a0>:0                                                                                  
         at Microsoft.Win32.KeyHandler..ctor (Microsoft.Win32.RegistryKey rkey, System.String basedir, System.Boolean is_volatile) [0x00038] in <efe941bb62534dc3a62ceb1a818964a0>:0                    
          --- End of inner exception stack trace ---                                                
         at Microsoft.Win32.KeyHandler..ctor (Microsoft.Win32.RegistryKey rkey, System.String basedir, System.Boolean is_volatile) [0x0004d] in <efe941bb62534dc3a62ceb1a818964a0>:0                    
         at Microsoft.Win32.KeyHandler..ctor (Microsoft.Win32.RegistryKey rkey, System.String basedir) [0x00000] in <efe941bb62534dc3a62ceb1a818964a0>:0                                                
         at Microsoft.Win32.KeyHandler.Lookup (Microsoft.Win32.RegistryKey rkey, System.Boolean createNonExisting) [0x000bf] in <efe941bb62534dc3a62ceb1a818964a0>:0                                    
         at Microsoft.Win32.UnixRegistryApi.OpenSubKey (Microsoft.Win32.RegistryKey rkey, System.String keyname, System.Boolean writable) [0x00000] in <efe941bb62534dc3a62ceb1a818964a0>:0             
         at Microsoft.Win32.RegistryKey.OpenSubKey (System.String name, System.Boolean writable) [0x0001b] in <efe941bb62534dc3a62ceb1a818964a0>:0                                                      
         at Microsoft.Win32.RegistryKey.OpenSubKey (System.String name) [0x00000] in <efe941bb62534dc3a62ceb1a818964a0>:0                                                                               
         at (wrapper remoting-invoke-with-check) Microsoft.Win32.RegistryKey.OpenSubKey(string)     
         at UnrealBuildTool.AndroidProjectGenerator..ctor (Tools.DotNETCommon.CommandLineArguments Arguments) [0x0001b] in <3fc5a524c85a4129a6c25f1773cbe451>:0                                         
         at (wrapper managed-to-native) System.Reflection.RuntimeConstructorInfo.InternalInvoke(System.Reflection.RuntimeConstructorInfo,object,object[],System.Exception&)                             
         at System.Reflection.RuntimeConstructorInfo.InternalInvoke (System.Object obj, System.Object[] parameters, System.Boolean wrapExceptions) [0x00005] in <efe941bb62534dc3a62ceb1a818964a0>:0    
          --- End of inner exception stack trace ---
         at System.Reflection.RuntimeConstructorInfo.InternalInvoke (System.Object obj, System.Object[] parameters, System.Boolean wrapExceptions) [0x0001a] in <efe941bb62534dc3a62ceb1a818964a0>:0 
         at System.Reflection.RuntimeConstructorInfo.DoInvoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00086] in <efe941bb62534dc3a62ceb1a818964a0>:0 
         at System.Reflection.RuntimeConstructorInfo.Invoke (System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <efe941bb62534dc3a62ceb1a818964a0>:0 
         at System.RuntimeType.CreateInstanceImpl (System.Reflection.BindingFlags bindingAttr, System.Reflection.Binder binder, System.Object[] args, System.Globalization.CultureInfo culture, System.Object[] activationAttributes, System.Threading.StackCrawlMark& stackMark) [0x0022b] in <efe941bb62534dc3a62ceb1a818964a0>:0 
         at System.Activator.CreateInstance (System.Type type, System.Reflection.BindingFlags bindingAttr, System.Reflection.Binder binder, System.Object[] args, System.Globalization.CultureInfo culture, System.Object[] activationAttributes) [0x0009c] in <efe941bb62534dc3a62ceb1a818964a0>:0 
         at System.Activator.CreateInstance (System.Type type, System.Object[] args) [0x00000] in <efe941bb62534dc3a62ceb1a818964a0>:0 
         at UnrealBuildTool.GenerateProjectFilesMode.Execute (Tools.DotNETCommon.CommandLineArguments Arguments) [0x001d0] in <3fc5a524c85a4129a6c25f1773cbe451>:0 
         at UnrealBuildTool.UnrealBuildTool.Main (System.String[] ArgumentsArray) [0x002bb] in <3fc5a524c85a4129a6c25f1773cbe451>:0
==> ERROR: A failure occurred in prepare().
    Aborting...
:: Packages failed to build: unreal-engine-4.26.2-2

@urbenlegend I need more from the log than this to try to help. I turned off installing patches by default in case that caused your problems.

I am getting this build error with 4.26.2-2 that I did not get when I successfully built 4.26.2-1:

ERROR: Unhandled exception: System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.Security.SecurityException: No access to the given key ---> System.UnauthorizedAccessException: Access to the path '/etc/mono/registry/LocalMachine' is denied. ---> System.IO.IOException: Permission denied

The directory /etc/mono/registry doesn't even exist.

@pyrow try ./GenerateProjectFiles.sh -makefile -CLion -ForceUseSystemCompiler

If your generating for a project try:

./GenerateProjectFiles.sh -project="/path/to/project/project.uproject" -ForceUseSystemCompiler -game -engine -makefile -CLion

That command will also give an xml file you can setup to use it from the engine.

Try compiling with make make ProjectName ARGS=-ForceUseSystemCompiler; make ProjectNameEditor ARGS=-ForceUseSystemCompiler from the command line to test too. If that doesn't compile then there's a bug in your code somewhere.

Remove -ForceUseSystemCompiler if you're using the provided compiler.

@AverytheFurry @zerophase that's what I did. chmod -R 770 /opt/unreal-engine.

However I am getting two errors around creating a C++ class and some errors being shifted to Tamil charset... https://bbs.archlinux.org/viewtopic.php?id=266035 https://bbs.archlinux.org/viewtopic.php?pid=1970928#p1970928