Swapchain creation fails on my device (NVIDIA GTX 1060) with the surface created by the SFML window.
I tested it on my other PC (with an integrated GPU) and I also swapped the whole sf::WindowBase I was using with a GLFW implementation - both worked fine.
I got a VK_ERROR_VALIDATION_FAILED_EXT result combined with the following validation layer message: "vkCreateSwapchainKHR: internal drawable creation failed".
The source code is attached in a zip file.