In what top scientists are calling “fucking stupid”, Solaris can’t handle disks that used to have non-solaris stuff on them without being wiped first.

I thought only the windows installer borked if the partition table looked weird, but no! The installer could not see the disk, and I was dropped into a dtterm where I had to do dd if=/dev/zero of=/dev/dsk/c0t0d0 bs=1048576 and reboot.

So… wipe the disk before trying to install Solaris.