you should replace any instances of PACKAGE with libgnomecanvas. Furthermore, when you come to the point where you shall perform the apt-get source command you shall do it like this
apt-get source libgnomecanvas libgnomecanvas2-0
And you should do the apt-get build-dep like this
apt-get build-dep libgnomecanvas2-0
you should replace any instances of PACKAGE with libgnomecanvas.
Furthermore, when you come to the point where you shall perform the apt-get
source command you shall do it like this
apt-get source libgnomecanvas libgnomecanvas2-0
And you should do the apt-get build-dep like this
apt-get build-dep libgnomecanvas2-0