GLSL shader version 4.30 not supported - opengl

Question

I have an Intel HD4400 graphics card in my laptop. When I run glxinfo | grep "OpenGL", I get
OpenGL vendor string: Intel Open Source Technology Center
OpenGL renderer string: Mesa DRI Intel(R) Haswell Mobile
OpenGL core profile version string: 4.5 (Core Profile) Mesa 18.0.0-rc5
OpenGL core profile shading language version string: 4.50
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile
OpenGL core profile extensions:
OpenGL version string: 3.0 Mesa 18.0.0-rc5
OpenGL shading language version string: 1.30
OpenGL context flags: (none)
OpenGL extensions:
OpenGL ES profile version string: OpenGL ES 3.1 Mesa 18.0.0-rc5
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.10
OpenGL ES profile extensions:
This should mean that my graphics card can support GLSL version 4.30, right? However, my shader compilation fails with the following message
error: GLSL 4.30 is not supported. Supported versions are: 1.10, 1.20, 1.30, 1.00 ES, 3.00 ES, and 3.10 ES
In my code, I do set the context profile to core, with the following statement
SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE)
after which I set the context major and minor versions to 4 and 3, respectively.
Any ideas? I am on Ubuntu 18.04. I thought it might be the graphics drivers that are not up to date, but if they are not up to date, then would glxinfo still tell me that version 4.50 is supported? It also seems like Ubuntu has the latest Intel graphics drivers installed already, and I do not want to risk installing graphics drivers that might break my display.
Additional Info:
I ran this exact code on another machine, and it worked perfectly (and I am quite sure that that machine does not support GL 4.3 compatible). I therefore do not believe that it is the way I created my context. Here is the code where I set my profile context version:
void set_gl_attribs()
{
if (SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE))
{
cout << "Could not set core profile" << endl;
}
if (SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 4))
{
cout << "Could not set GL major version" << endl;
}
if (SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3))
{
cout << "Could not set GL minor version" << endl;
}
}
And this is where I call the code (before I call any other SDL or OpenGL functions):
SDL_Init(SDL_INIT_EVERYTHING);
window = SDL_CreateWindow("Sphere", 100, 100, width, height, SDL_WINDOW_OPENGL);
gl_context = SDL_GL_CreateContext(window);
//SDL_HideWindow(window);
set_gl_attribs(); // where I set the context, as shown above
SDL_GL_SetSwapInterval(1);
glewExperimental = GL_TRUE;
GLuint glew_return = glewInit();

Answer 1

The setup code is incorrect. You must choose a core profile context before creating the context, changing the profile after the context exists is too late and it will not work. Also, according to the SDL2 documentation, all calls to SDL_GL_SetAttribute must be made before the window is created via SDL_CreateWindow.
Move all calls to SDL_GL_SetAtrribute so they are before SDL_CreateWindow.
The reason that this incorrect code appears to work on other machines is because different drivers provide different versions of OpenGL depending on whether you ask for a compatibility or code profile context.
Mesa will only provide 3.0 for compatibility contexts,
macOS will only provide 2.1 for compatibility contexts,
NVidia and AMD drivers on Windows will provide the latest version they support.