glad causing problems when I use gladLoadGLLoader

Question

I've been trying to use glad, however I get all sorts of issues when I use it. First off, I get no errors by just including it

#include <glad/glad.h>
#include <GLFW/glfw3.h>

I only start to get problems when I use it

if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
{
    std::cout << "Failed to initalize Glad" << std::endl;
    return -1;
}

Then I get the error:

Undefined symbols for architecture x86_64:
  "_gladLoadGLLoader", referenced from:
      _main in main-479587.o
  "_glad_glClear", referenced from:
      _main in main-479587.o
  "_glad_glClearColor", referenced from:
      _main in main-479587.o
  "_glad_glViewport", referenced from:
      _main in main-479587.o
ld: symbol(s) not found for architecture x86_64

After that I tried switch place of the includes:

#include <GLFW/glfw3.h>
#include <glad/glad.h>

This gives me the same error.

#ifdef __APPLE__
/* Defined before OpenGL and GLUT includes to avoid deprecation messages */
#define GL_SILENCE_DEPRECATION
#include <OpenGL/gl.h>
#include <GLUT/glut.h>
#else
#include <GL/gl.h>
#include <GL/glut.h>
#endif
#include <GLFW/glfw3.h>
#include <glad/glad.h>

This gives me:

error: OpenGL header already included, remove this include, glad already provides it

So I tried using #define GLFW_INCLUDE_NONE, but that did nothing. Was I maybe missing some gladInit function or something?

Here's the full code example:

#ifdef __APPLE__
/* Defined before OpenGL and GLUT includes to avoid deprecation messages */
#define GL_SILENCE_DEPRECATION
#include <OpenGL/gl.h>
#include <GLUT/glut.h>
#else
#include <GL/gl.h>
#include <GL/glut.h>
#endif
#define GLFW_INCLUDE_NONE
#include <GLFW/glfw3.h>
#include <glad/glad.h>
#include <iostream>

int main(void)
{
    if (!glfwInit())
    {
        std::cout << "Failed to initalize GLFW" << std::endl;
        return -1;
    }

    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 6);

    const int windowWidth = 1280;
    const int windowHeight = 720;
    const char* windowTitle = "Game";

    GLFWwindow* window = glfwCreateWindow(
        windowWidth,
        windowHeight,
        windowTitle,
        nullptr,
        nullptr
    );

    if (window == nullptr)
    {
        std::cout << "Failed to create GLFW window." << std::endl;
        glfwTerminate();
        return -1;
    }

    glfwMakeContextCurrent(window);

    if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
    {
        std::cout << "Failed to initalize Glad" << std::endl;
        return -1;
    }

    glViewport(0, 0, windowWidth, windowHeight);

    while (!glfwWindowShouldClose(window))
    {
        glClearColor(250 / 255, 119 / 255, 110 / 255, 1);
        glClear(GL_COLOR_BUFFER_BIT);

        glfwSwapBuffers(window);
        glfwPollEvents();
    }

     glfwTerminate();

    return 0;

}