FetchContent does not work?

[taehyounpark]

Sorry if this is actually a general CMake question than the library itself. I'm trying to follow the FetchContent way to pull nlohmann::json in to my project:

  # nlohmann::json
  include(FetchContent)
  FetchContent_Declare(json URL https://github.com/nlohmann/json/releases/download/v3.11.3/json.tar.xz)
  FetchContent_MakeAvailable(json)
  
  target_link_libraries(
  queryosity_extensions
  INTERFACE queryosity::queryosity
  PRIVATE nlohmann_json::nlohmann_json
)

But this does not allow the headers to be found. Only when I also do:

target_include_directories(
  queryosity_extensions 
  PUBLIC ${CMAKE_CURRENT_SOURCE_DIR} ${nlohmann_json_SOURCE_DIR}/include
)

the compilation works. It was my understanding that the full library name nlohmann_json::nlohmann_json should be enough for it to be discovered, am I missing something here? Thanks in advance.

[nlohmann]

This is how I use the library in a project:

cmake_minimum_required(VERSION 3.20)
project(json_test)

include(FetchContent)

FetchContent_Declare(json URL https://github.com/nlohmann/json/releases/download/v3.11.2/json.tar.xz)
FetchContent_MakeAvailable(json)

add_executable(json_test main.cpp)
target_link_libraries(json_test PUBLIC nlohmann_json::nlohmann_json)

and then in main.cpp

#include <nlohmann/json.hpp>

[taehyounpark]

So changing PRIVATE to PUBLIC was the solution (at least for me). According to this post there seems to be no reason to not do this when we'll pretty much always be working with the JSON objects from this library?