UbaSessionServer - ASSERT by Cross-Compile Toolchain imd UE5.5

Development Asset Creation
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1

Hi UDN,

We have a problem trying to compile our aplication for Linux with the Cross-Compile Toolchain.

We Use UE5.5.4 with v23 clang-18.1.0-based. Whenever we try to compile we have the error shown in the image.

This problem is new. It’s been two months since we last compiled our app for Linux, and this didn’t happen.

We cannot compile an empty project either.

[Image Removed]

What could be causing this error? What can we do?

Regards

2

Hey there,

Confirming some ground truth here:

  • You’ve been on 5.5.4 thorughout - since it last worked and now
  • Your Linux_SDK installed version has always been v23_clang-18.1.0-rockylinux8
  • I suspect you’ve a new windows update? Can you confirm your version?

This feels similar to this [related [Content removed] You’ll need to adopt the patch and generate your binaries. From Jack Anderson:

`… here’s the minimal patch procedure to stop the dump_syms crash:

First, run the .bat file mentioned here to set up the UBA solution:

Then edit UbaDetoursFunctionsMiMalloc.inl so Detoured__realloc_base is implemented as such:

void* Detoured__realloc_base(void* memblock, size_t size)
{
if (IsInMiMalloc(memblock))
return mi_realloc(memblock, size);
else
return True__realloc_base(memblock, size);
}

Then build just the UbaDetours target. The .dll is output at Engine\Binaries\Win64\UnrealBuildAccelerator\x64\UbaDetours.dll

Rebuilding UnrealBuildTool is also necessary so it copies this .dll into `Engine\Binaries\DotNET\UnrealBuildTool\runtimes\win-x64\native\UbaDetours.dll``

We will need to produce a new binary for 5.5.X. I’m still looking at this.

Julian

3

Hi Julian,

About your questions

You’ve been on 5.5.4 thorughout - since it last worked and now -> Yes

Your Linux_SDK installed version has always been v23_clang-18.1.0-rockylinux8 -> Yes

I suspect you’ve a new windows update? Can you confirm your version? -> Yes

Edition: Win 11 Pro

Version: 24H2

Build 26100.4349

and the last update was the KB5060842

Yes, the problem is very similar to the one described in the link.

Regards

4

Hey there,

Yes I think this will be the issue. I’ll regenerate some binaries today and send them over to see if it works.

Kind regards,

Julian

5

Hey there,

Please give the attached binaries a try on your end (since I cannot update my machine at the moment). They should be here.

Kind regards,

Julian

6

Hi Julian,

We tested the binaries on one of our machines with the problem. We can compile an empty project for linux, but unfortunately our project presents the same crash.

In my machine i uninstalled the update KB5060842 and i can compile again.

Our CI/CD pipeline servers are running Windows Server and have not had any issues.

Are you going to release a hotfix version of UE5.5 with the solution to the problem?

Kind regards,

Luis

7

Hi there Luis,

The attached binaries are indeed the patched version (fix that went into 5.6). Are you copying them over into the binaries folder? Are you also disabling the mimalloc via the PATH_TO_ROOT\Engine\Binaries\Win64\UnrealBuildAccelerator\x64\UbaHost.toml?

[Session] AllowCustomAllocator = falseI’ll produce a separate patch to see if this works.

Kind regards,

Julian

8

Have same problem, but only compile linux builds on AMD cpu (9950x).

Windows compile without any problems.