- https://docs.unrealengine.com/en-US/Platforms/Linux/GettingStarted/index.html grab v13 clang toolchain under unreal 4.22 section
open admin command promp and :
C:\WINDOWS\system32> setx LINUX_MULTIARCH_ROOT C:\UnrealToolchains\v13_clang-7.0.1-centos7\