Debian install 5 works, so I need to check the difference. Here is the one from alpha 6:
$ cat yaboot.conf ## yaboot.conf generated by debian-installer ## ## run: "man yaboot.conf" for details. Do not make changes until you have!! ## see also: /usr/share/doc/yaboot/examples for example configurations. ## ## For a dual-boot menu, add one or more of: ## bsd=/dev/hdaX, macos=/dev/hdaY, macosx=/dev/hdaZ boot="/dev/disk/by-id/ata-WDC_WD800BEVE-00A0HT0_WD-WXR1EB0SNY82-part2" device=/pci@f4000000/ata-6@d/@0 partition=3 root="UUID=5b3c49c3-895d-4d1d-a045-99fac6e904ad" timeout=50 install=/usr/lib/yaboot/yaboot magicboot=/usr/lib/yaboot/ofboot enablecdboot image=/boot/vmlinux label=Linux read-only initrd=/boot/initrd.img image=/boot/vmlinux.old label=old read-only initrd=/boot/initrd.img.old
