SDL_GL_SetAttribute causes some opengl functions to be null - c++

Question

Setting values higher, for example 32 for SDL_GL_DEPTH_SIZE causes glCreateShader to be null.
I don't know what is causing this behavior, because I don't get any errors while setting attributes and creating context. Here's a minimalistic example.
#include <iostream>
#include <SDL2/SDL.h>
#include <GL/glew.h>
#include <SDL2/SDL_opengl.h>
const int WIDTH = 800;
const int HEIGHT = 600;
int main(int argc, char **argv)
{
SDL_Init(SDL_INIT_EVERYTHING);
int response;
response = SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK,
SDL_GL_CONTEXT_PROFILE_CORE);
response = SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
response = SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);
response = SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
if (response < 0) {
std::cout << "Setting Attribute: DEPTH_SIZE Failed\n";
return 0;
}
SDL_Window *window = SDL_CreateWindow("TestApp", WIDTH >> 1, HEIGHT >> 1, WIDTH, HEIGHT, SDL_WINDOW_OPENGL);
if (window == nullptr) {
std::cout << "window not setup\n";
return 0;
}
SDL_GLContext context = SDL_GL_CreateContext(window);
if (context == nullptr) {
std::cout << "context failed\n";
return 0;
}
glewExperimental = GL_TRUE;
if (GLEW_OK != glewInit()) {
std::cout << "Failed to initialize glew\n";
return 0;
}
glViewport(0, 0, WIDTH, HEIGHT);
int value;
SDL_GL_GetAttribute(SDL_GL_DEPTH_SIZE, &value);
std::cout << "Querying Depth size: " << value << "\n";
std::cout << "glEnable: " << (glEnable ? "Available" : "NULL") << "\n";
std::cout << "glCreateShader: " << (glCreateShader ? "Available" : "NULL") << "\n";
SDL_GL_DeleteContext(context);
SDL_DestroyWindow(window);
SDL_Quit();
return 0;
}
output for DEPTH_SIZE = 24 bits
Querying Depth size: 24
glEnable: Available
glCreateShader: Available
output for DEPTH_SIZE = 32 bits
Querying Depth size: 32
glEnable: Available
glCreateShader: NULL