Arch Linux

NeonGoose

Member

Registered: 2025-03-18

Posts: 1

Unreal Engine 5.5.4 wont build on Arch, gives ISPC errors

Hi,
I am on freshly updated Arch, tried to build UE5 from source and keep getting errors bellow, tried various chatbots and docs but it just wont work.

Compile Module.Chaos.10.cpp
In file included from /home/goose/UnrealEngine/Engine/Intermediate/Build/Linux/x64/UnrealEdit
or/Development/Chaos/Module.Chaos.10.cpp:4:
/home/goose/UnrealEngine/Engine/Source/Runtime/Experimental/Chaos/Private/Chaos/Joint/PBDJoin
tSolverGaussSeidel.cpp:11:10: fatal error: ‘PBDJointSolverGaussSeidel.ispc.generated.h’ file
not found

ispc FloatArrayMath.ispc -o FloatArrayMath.o -h FloatArrayMath.ispc.generated.h
Warning: No --target specified on command-line. Using default system target
“avx512icl-x16”.
FloatArrayMath.ispc:3:10: fatal error: ‘Math/Aossoa.isph’ file not found
3 | include “Math/Aossoa.isph”
| ^~~~~~~~~~~~~~~~~~
FloatArrayMath.ispc:258:40: Error: Undeclared symbol
“FLOAT_SMALL_NUMBER”.
const uniform float Scale = 1.f / max(FLOAT_SMALL_NUMBER, MaxValue - MinValue);
^^^^^^^^^^^^^^^^^^

FloatArrayMath.ispc:258:36: Error: Ambiguous use of overloaded function
“max”.
const uniform float Scale = 1.f / max(FLOAT_SMALL_NUMBER, MaxValue - MinValue);
^^^

ISPC version
Intel(r) Implicit SPMD Program Compiler (Intel(r) ISPC), 1.25.3 (build commit 12aac3343c0ea84
9 @ 20250106, LLVM 19.1.6

ISPC is up-to-date, it is in path, tried to edit target to remove it, had no effect, never had this issue on Windows, few months ago worked on Ubuntu, no idea whats broken, please help.

WorMzy

Administrator

From: Scotland

Registered: 2010-06-16

Posts: 13,187

Website

Re: Unreal Engine 5.5.4 wont build on Arch, gives ISPC errors

Mod note: moving to AUR Issues

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