If the output does not have a CONNECTOR_ID atom, then this function fails (giving back a 0 VkDisplayKHR) but it returns VK_SUCCESS nonetheless.
Passing this VkDisplayKHR into vkAcquireXlibDisplayEXT later then segfaults mesa.
There is an MR opened about this : https://gitlab.freedesktop.org/mesa/mesa/merge_requests/385
Unfortunately we need a spec update first as there is no error code defined for this function to fail. There is an issue opened about this on the khronos group gitlab.
I think the behavior of the driver follows the spec, so I will close.
When the spec is updated we'll update the driver.