UE5 GenerateProjectFiles.command fails to build UnrealBuildTool when compiling from source on MacOS. Throws "Failed to load JIT compiler" and "dotnet command failed with errorcode 134"

Trying to set up Unreal Engine 5 on my MacBook so I can use UnrealPak.exe to open Unreal Engine .pak files. I’m compiling from source as instructed. I cloned from github using the command “git clone https://github.com/EpicGames/UnrealEngine.git” in Terminal and used a classic Personal Access Token. Then I ran Setup.command and it seemed to run without issue.

When I tried to run GenerateProjectFiles.command I get a long sequence that ends with “dotnet command failed with errorcode 134 after 3 attempts”

I’ve tried googling some keywords but nothing seems to match my problem. Everything similar seems to be a specific use case and doesn’t explain the meaning of the error code I got. Allegedly it might have something to do with incompatabilities regarding x86 based code and ARM64 based code. I tried updating my OS and XCode but that hasn’t solved the issue. The closest other explanation I got was “NETSDK1134: Building a solution with a specific RuntimeIdentifier is not supported. If you would like to publish for a single RID, specify the RID at the individual project level instead.” I have no idea what code or command to use to to resolve whatever syntax related issue this is describing. I even tried the workaround instructions for issue UE-377426 even though it doesn’t seem to be related and that still doesn’t work.

Is there a way to fix this, or did Epic Games unknowingly stuff x86 code into a compiling command intended for Apple Silicon?

Here are my environment details:

OS version: MacOS Tahoe 26.6.2
XCode version: 26.2

Clang Version Info: Command returns “Apple clang version 17.0.0 (clang-1700.6.3.2)
Target: arm64-apple-darwin25.6.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin”

UE5 version: I can’t find the area inside the UnrealEngine folder which specifies

Here is the sequence in question:

Last login: Wed Aug 26 18:43:16 on console

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Mac:~ [My real name]$ /Users/[My real name]/Downloads/UnrealEngine/GenerateProjectFiles.command ; exit;

Setting up Unreal Engine project files…

Setting up bundled DotNet SDK
/Users/[My real name]/Downloads/UnrealEngine/Engine/Binaries/ThirdParty/DotNet/10.0/mac-arm64
Fatal error.
Failed to load JIT compiler
at System.Runtime.CompilerServices.StaticsHelpers.GetGCThreadStaticBase(System.Runtime.CompilerServices.MethodTable*)
at System.Globalization.CultureInfo.get_CurrentUICulture()
at System.TimeZoneInfo.GetUtcStandardDisplayName()
at System.TimeZoneInfo.CreateUtcTimeZone()
at System.TimeZoneInfo..cctor()
at System.DateTime.get_Now()
at Microsoft.DotNet.Cli.Program.Main(System.String)
dotnet command failed with errorcode 134. Retrying in 1 seconds… (1/3)
Fatal error.
Failed to load JIT compiler
at System.Runtime.CompilerServices.StaticsHelpers.GetGCThreadStaticBase(System.Runtime.CompilerServices.MethodTable*)
at System.Globalization.CultureInfo.get_CurrentUICulture()
at System.TimeZoneInfo.GetUtcStandardDisplayName()
at System.TimeZoneInfo.CreateUtcTimeZone()
at System.TimeZoneInfo..cctor()
at System.DateTime.get_Now()
at Microsoft.DotNet.Cli.Program.Main(System.String)
dotnet command failed with errorcode 134. Retrying in 1 seconds… (2/3)
Fatal error.
Failed to load JIT compiler
at System.Runtime.CompilerServices.StaticsHelpers.GetGCThreadStaticBase(System.Runtime.CompilerServices.MethodTable*)
at System.Globalization.CultureInfo.get_CurrentUICulture()
at System.TimeZoneInfo.GetUtcStandardDisplayName()
at System.TimeZoneInfo.CreateUtcTimeZone()
at System.TimeZoneInfo..cctor()
at System.DateTime.get_Now()
at Microsoft.DotNet.Cli.Program.Main(System.String)
dotnet command failed with errorcode 134 after 3 attempts

cat: /var/folders/7k/gbsw3ww52f97m7ydh211bjmh0000gn/T/tmp.jxh1dBZjCP/.dep.csv: No such file or directory
Rebuilding: UnrealBuildTool assembly not found
Building UnrealBuildTool…
Fatal error.
Failed to load JIT compiler
at System.Runtime.CompilerServices.StaticsHelpers.GetGCThreadStaticBase(System.Runtime.CompilerServices.MethodTable
)
at System.Globalization.CultureInfo.get_CurrentUICulture()
at System.TimeZoneInfo.GetUtcStandardDisplayName()
at System.TimeZoneInfo.CreateUtcTimeZone()
at System.TimeZoneInfo..cctor()
at System.DateTime.get_Now()
at Microsoft.DotNet.Cli.Program.Main(System.String)
dotnet command failed with errorcode 134. Retrying in 1 seconds… (1/3)
Fatal error.
Failed to load JIT compiler
at System.Runtime.CompilerServices.StaticsHelpers.GetGCThreadStaticBase(System.Runtime.CompilerServices.MethodTable*)
at System.Globalization.CultureInfo.get_CurrentUICulture()
at System.TimeZoneInfo.GetUtcStandardDisplayName()
at System.TimeZoneInfo.CreateUtcTimeZone()
at System.TimeZoneInfo..cctor()
at System.DateTime.get_Now()
at Microsoft.DotNet.Cli.Program.Main(System.String)
dotnet command failed with errorcode 134. Retrying in 1 seconds… (2/3)
Fatal error.
Failed to load JIT compiler
at System.Runtime.CompilerServices.StaticsHelpers.GetGCThreadStaticBase(System.Runtime.CompilerServices.MethodTable*)
at System.Globalization.CultureInfo.get_CurrentUICulture()
at System.TimeZoneInfo.GetUtcStandardDisplayName()
at System.TimeZoneInfo.CreateUtcTimeZone()
at System.TimeZoneInfo..cctor()
at System.DateTime.get_Now()
at Microsoft.DotNet.Cli.Program.Main(System.String)
dotnet command failed with errorcode 134 after 3 attempts

UnrealBuildTool compilation failed
GenerateProjectFiles ERROR: Failed to build UnrealBuildTool
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