CMake - Include directories outside project

Question

So I want to include a global header file that is in a different folder. The code for the CMakeList.txt is below. In my .cpp when I include something from the local include folder it works, but not for the something that is in a different folder.

cmake_minimum_required(VERSION 2.8)

#Project name
project(Server-Client)

#Add all cpp files as source files
file(GLOB_RECURSE SOURCES "src/*.cpp")

#Build executable 'Server' with all files in SOURCES
add_executable(Server ${SOURCES})

#Include all files in include directory
include_directories("include")

target_include_directories(Server PUBLIC "../../GlobalFiles/include")

find_package(Threads REQUIRED)

#Build executable 'localization' with all files in SOURCES
target_link_libraries(Server ${CMAKE_THREAD_LIBS_INIT})

Answer 1

Don't use a relative paths, instead use CMAKE_CURRENT_SOURCE_DIR variable like this:

target_include_directories(Server PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}/../../GlobalFiles/include")

Other than that, it might be a good idea to use a Macro to find the global header you are looking for.