Cannot link due to undefined references

As per the thread title, I’m having troubles with undefined references to the following symbols:
Obviously, I’m linking against libvulkan. I also tried to find where they are defined by using

readelf -Ws

on Linux, but my search failed. Anyone could give me any hint?

These are functions from the VK_EXT_DEBUG_MARKER extensions, and as such are not part of the Vulkan core library. This means that you have to load the function pointers yourself:

pfnDebugMarkerSetObjectTag = (PFN_vkDebugMarkerSetObjectTagEXT)vkGetDeviceProcAddr(device, "vkDebugMarkerSetObjectTagEXT");
pfnDebugMarkerSetObjectName = (PFN_vkDebugMarkerSetObjectNameEXT)vkGetDeviceProcAddr(device, "vkDebugMarkerSetObjectNameEXT");
pfnCmdDebugMarkerBegin = (PFN_vkCmdDebugMarkerBeginEXT)vkGetDeviceProcAddr(device, "vkCmdDebugMarkerBeginEXT");
pfnCmdDebugMarkerEnd = (PFN_vkCmdDebugMarkerEndEXT)vkGetDeviceProcAddr(device, "vkCmdDebugMarkerEndEXT");
pfnCmdDebugMarkerInsert = (PFN_vkCmdDebugMarkerInsertEXT)vkGetDeviceProcAddr(device, "vkCmdDebugMarkerInsertEXT");

The solution was so obvious (…EXT)! So that’s not a problem of mine only, but of the vkcpp project too (I’m currently working on a fork of that project).
Thank you Sascha.