Trying to use IOError.from_errno results in a C error:

int main (string[] args) {                                                      
    throw IOError.from_errno (Posix.errno);                                     
}

Output:

ioerror.vala:2.5-2.43: warning: unhandled error `GLib.IOError'
    throw IOError.from_errno (Posix.errno);
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
/home/jens/Source/rygel/ioerror.vala.c: In function ‘_vala_main’:
/home/jens/Source/rygel/ioerror.vala.c:30:9: error: incompatible types when assigning to type ‘struct GError *’ from type ‘GIOErrorEnum’
/home/jens/Source/rygel/ioerror.vala.c: In function ‘main’:
/home/jens/Source/rygel/ioerror.vala.c:41:2: warning: ‘g_type_init’ is deprecated (declared at /opt/rygel-stable/include/glib-2.0/gobject/gtype.h:669) [-Wdeprecated-declarations]
error: cc exited with status 256
Compilation failed: 1 error(s), 1 warning(s)