gstvkwindow_win32.c(166): error C2065: 'msg_source': undeclared identifier
Remove any references to CamelTypePrivate from the public CamelType struct. They can be accessed as needed using camel_type_get_instance_private().
It's almost a fork of glwindow_win32 implementation. To build on Windows, Vulkan SDK (at https://vulkan.lunarg.com/sdk/home) and VK_SDK_PATH environment are required. Note that VK_SDK_PATH environment setting is a part of the SDK installation.