[Vala] How to get OS Information in Vala?

[Александер Пономарёв <shootnix gmail com>]

Hi folks,
I'm sorry for a newbie question, but I really can't find it in google:
how to get information about operating system in vala?
Trying Osinfo:

$ valac --pkg osinfo-1.0 myprogram.vala

but it doesn't work:

libosinfo-1.0.vapi:150.69-150.84: error: The type name
`GLib.Cancellable' could not be found
                public static Osinfo.Media create_from_location (string location,
GLib.Cancellable? cancellable) throws GLib.Error;
                
^^^^^^^^^^^^^^^^
libosinfo-1.0.vapi:151.95-151.110: error: The type name
`GLib.Cancellable' could not be found
                public static async Osinfo.Media create_from_location_async (string
location, int priority, GLib.Cancellable? cancellable) throws
GLib.Error;
                
                       ^^^^^^^^^^^^^^^^
Compilation failed: 2 error(s), 0 warning(s)

Can someone help me?

p.s. happy new year to all ;-)