> What am I doing wrong?

Asking for help in installing OpenBSD on a NetBSD mailing list?   :')

How exactly are you invoking disklabel?   If you have a disklabel
template file, and OpenBSD disklabel is sufficiently similar to NetBSD
disklabel, then you need to do a disklabel -R /dev/rz2c yourlabel
(where yourlabel is the name of the template file).

You've got to get past the disklabel stage in order to do your
install.   The install script that you're using isn't available on
NetBSD, so we can't help you debug it.   If you want to do the install
manually, you can probably just newfs a /, /var and /usr, mount them
all under /mnt, extract the tar files there, make yourself a /mnt/dev
(MAKEDEV all, or something like that), hack the files in /etc, and go.

			       _MelloN_