glfwInit() failing with Wayland: Failed to connect to display

I’m attempting to initialize GLFW on an X11 session, but it is failing with the following:

error code: 65544
description: Wayland: Failed to connect to display

I have the following environment variables set:

XDG_SESSION_TYPE=x11
GDK_BACKEND=x11

Code segment:

    int code;
    int ret = glfwInit();
    if (ret == GLFW_FALSE) {
        code = glfwGetError(&description);
        std::cerr << "glfwInit return error, code " << code;
        if (description)
            std::cerr << ": " << description;
        std::cerr << std::endl;
        abort();
    }

On Arch Linux, the glfw package supports both X11 and Wayland AFAIK.

Did you set the init hint GLFW_PLATFORM? It may be that since that was introduced the environment variable doesn’t matter. In any way, I would so something like this:

if(glfwPlatformSupported(GLFW_PLATFORM_WIN32)) glfwInitHint(GLFW_PLATFORM, GLFW_PLATFORM_WIN32);
else if(glfwPlatformSupported(GLFW_PLATFORM_COCOA)) glfwInitHint(GLFW_PLATFORM, GLFW_PLATFORM_COCOA);
else if(glfwPlatformSupported(GLFW_PLATFORM_X11)) glfwInitHint(GLFW_PLATFORM, GLFW_PLATFORM_X11);
else if(glfwPlatformSupported(GLFW_PLATFORM_WAYLAND)) glfwInitHint(GLFW_PLATFORM, GLFW_PLATFORM_WAYLAND);
else {
        fprintf(stderr, "Error: could not find acceptable platform for GLFW\n");
        abort();
}

before the code you have written above (maybe rearrange the cases for whatever priority you want to have). Maybe you can try if somthing like that helps your case.

description: Wayland: Failed to connect to display

This error description indicates that GLFW was compiled with only Wayland support. What does the GLFW version string say?