Two days tyring to figure this out.

[AnonymousRonin]

CMake Error at CMakeLists.txt:40 (FetchContent_Declare):
Unknown CMake command "FetchContent_Declare".

This must be absolutely vital to the whole build becuse the few lines are preventing the build. Quick question, why isn't this listed as dependancy? Where is it?

[MrSidims]

FetchContent_Declare is a part of cmake 3.13, see https://cmake.org/cmake/help/v3.13/module/FetchContent.html

Our cmake file has cmake_minimum_required(VERSION 3.13.4). Have you changed this line to compile the project on the older version of cmake?

[AnonymousRonin]

I'm not sure why, but when I downloaded llvm-project from the souce page rather that "git clone" is when the error occured. When I used git everything went fine.