How to use a package in a library

[silentstranger5]

I'm trying to figure out how to use vcpkg in my project.
I'm following this tutorial

When I follow it step by step, I've got no issues whatsoever. But I'm trying to do something different.
It looks like this:

main.cpp:

#include "hello.h"

int main(void)
{
	print_hello();
	return 0;
}

hello.h:

#include <fmt/core.h>

void print_hello(void);

hello.cpp:

#include "hello.h"

void print_hello(void)
{
	fmt::print("Hello, World!");
}

I know that it looks a bit weird, but this is a minimal reproducible example. The project I'm working on is a bit larger, so it makes more sense there. I'm trying to make a library from hello.cpp, link external fmt library to this library, and then link this library to main.cpp.

CMakeLists.txt:

cmake_minimum_required(VERSION 3.10)

project(hello)

find_package(fmt CONFIG REQUIRED)

add_executable(hello main.cpp)
add_library(hellolib hello.cpp)

target_link_libraries(hellolib PRIVATE fmt::fmt)
target_link_libraries(hello PRIVATE hellolib)

I know that I'm doing something wrong, but I'm not very familiar with CMake. That being said, I hope that it's possible to use vcpkg package with a library and not just with the main.cpp.

When I try to build the project, this is what I get:

C:\path\to\dir\hello.h(1): fatal error C1083: Cannot open include file: 'fmt/core.h': No such file or directory

So it seems like CMake can't find fmt header files when I try to include them in hello.h. However, when I include them in the main.cpp (and then use them here), there are no issues.

[silentstranger5]

I figured it out. I need to link fmt with hellolib and hello, and then link hellolib with hello. It can be done like so:

target_link_libraries(hellolib PUBLIC fmt::fmt)
target_link_libraries(hello PRIVATE hellolib)