[Linux] Build fails on UE 5.5: 'BlueNoise.h' not found & 'rpclib' linker error (__isoc23_strtol)

[bigbigworld123]

I am trying to compile Cosys-AirSim on Linux with Unreal Engine 5.5, but I encountered two blocking issues during the build process.

Environment

• OS: Linux (Ubuntu24.04)
• Unreal Engine version: 5.5.0
• Cosys-AirSim version: Main branch

Issue 1: 'BlueNoise.h' file not found
Issue 2: Linker error undefined symbol: __isoc23_strtol

[tuwi84]

1)in AirSim.Build.cs fix PrivateIncludePaths

` public AirSim(ReadOnlyTargetRules Target) : base(Target)
{
//bEnforceIWYU = true; //to support 4.16
PCHUsage = PCHUsageMode.UseExplicitOrSharedPCHs;

    bEnableExceptions = true;

    PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore", "ImageWrapper", "RenderCore", "RHI", "AssetRegistry", "PhysicsCore", "ChaosVehicles", "Landscape", "CinematicCamera" });
    PrivateDependencyModuleNames.AddRange(new string[] { "UMG", "Slate", "SlateCore", "RenderCore", "ChaosVehicles", "Renderer" });

    //suppress VC++ proprietary warnings
    PublicDefinitions.Add("_SCL_SECURE_NO_WARNINGS=1");
    PublicDefinitions.Add("_CRT_SECURE_NO_WARNINGS=1");
    PublicDefinitions.Add("HMD_MODULE_INCLUDED=0");

    PublicIncludePaths.Add(Path.Combine(AirLibPath, "include"));
    PublicIncludePaths.Add(Path.Combine(AirLibPath, "deps", "eigen3"));

    PrivateIncludePaths.AddRange(new string[] {
    Path.Combine(EngineDirectory, "Source/Runtime/Renderer/Private"),
    Path.Combine(EngineDirectory, "Source/Runtime/RenderCore/Private")
    });

    AddOSLibDependencies(Target);

    SetupCompileMode(CompileMode.HeaderOnlyWithRpc, Target);
}`

2. Fix __isoc23_strtol from librpc.a (glibc mismatch)

linker error because a prebuilt librpc.a was compiled against a newer glibc.

We use a pragmatic shim to unblock immediately.

Add a shim source file
Create:

/AirSimProject/Plugins/AirSim/Source/AirLib/deps/rpclib/shims/isoc23_shim.c

With contents:

#include <stdlib.h>

// Forward new GLIBC C23 symbol to classic strtol on older systems (e.g., glibc 2.35)
long __isoc23_strtol(const char* nptr, char** endptr, int base) {
    return strtol(nptr, endptr, base);
}

You can also place the file under Plugins/AirSim/Source/AirSim/ — Unreal will compile it into the module automatically.