OpenGL: Segmentation Fault (Core Dumped) when running - c++

Question

I am writing a game engine in C++ and OpenGL and when I open my first test window i receive this issue:
Segmentation fault (core dumped)
There is no error when compiling, and it compiles just fine. The problem lies when I go to open the window.
HOW TO REPRODUCE:
#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include <iostream>
void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{
glViewport(0, 0, width, height);
}
int main()
{
typedef void (*GL_GENBUFFERS) (GLsizei, GLuint*);
GL_GENBUFFERS glGenBuffers = (GL_GENBUFFERS) glfwGetProcAddress("glGenBuffers");
unsigned int buffer;
glGenBuffers(1, &buffer);
glfwInit();
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
GLFWwindow* window = glfwCreateWindow(800, 600, "BloodBunny", NULL, NULL);
if (window == NULL)
{
std::cout << "Failed to create GLFW window" << std::endl;
glfwTerminate();
return -1;
}
glfwMakeContextCurrent(window);
if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
{
std::cout << "Failed to initialize GLAD" << std::endl;
return -1;
}
while(!glfwWindowShouldClose(window))
{
glfwSwapBuffers(window);
glfwPollEvents();
}
glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
glViewport(0,0,800,600);
glfwTerminate();
return 0;
}

Answer 1

glfwGetProcAddress() will only (potentially, depending on the name requested and the GL version of the current context) return usable, non-NULL function-pointers if a GL context is current.
With GLFW you make a window's context current via glfwMakeContextCurrent() so if you truly want to grab your own pointer to glGenBuffers() you need to move the glfwGetProcAddress() call to after a successful glfwMakeContextCurrent():
...
glfwMakeContextCurrent(window);
...
typedef void (*GL_GENBUFFERS) (GLsizei, GLuint*);
GL_GENBUFFERS glGenBuffers = (GL_GENBUFFERS) glfwGetProcAddress("glGenBuffers");
unsigned int buffer;
glGenBuffers(1, &buffer);
...
...though honestly there's little point since you're calling gladLoadGLLoader() right after glfwMakeContextCurrent() which will populate a perfectly usable glGenBuffers() pointer at global scope all on its own.