[Vala] GVariant error while compiling

[Marco Trevisan (Treviño) <mail 3v1n0 net>]

When trying to compile the Variant example, I get an errror while
compiling the generated C (which is wrong), in fact I get this error:

variant-test.c: In function ‘_variant_new1’:
variant-test.c:142: error: too few arguments to function
‘g_variant_ref_sink’

The C code is:

static GVariant* _variant_new1 (const char* value) {
        return g_variant_ref_sink ();
}

Why is this happening?