What a journey it is to get MintPPC automatically installed. Yesterday I finally made a breakthrough. The installer is now able to detect my local repository, the Debian-ports repository, to add the required keys and to start downloading and installing all required packages to get to the MintPPC desktop. There is still one problem, which is the same for Debian: Grub. The recent debian-installers ditched yaboot for grub and we are now, after installing the system, left on our own to install the yaboot bootloader. I will try a little bit more to get the yaboot-installer to work in the recent debian-installer but if that fails, I will leave it at that.
There are some minor things that need to be done. I am working on that. One problem I encountered is that mint-artwork breaks the system. I will need to rebuild the package for recent sid. Some other small details are the configuration of the wallpaper for smaller monitors. If that is finished I will try to dump my installer iso somewhere in Google drive so you can start testing the alpha release.