I'm installing Debian, as I've done a million times, except this time I'm trying with full-disk encryption from the installation itself and partitioning manually, because I'm replacing an existing Linux partition (different distro) on a disk with all sorts of mystical partitions that I don't want to mess with. At any rate, I just need one partition for this installation, whose previous Linux distro I'm replacing with Debian.
However, I seem only able to set the target partition (/dev/nvme0n1p5) as the root partition (/) before I configure its encryption, but then finding myself unable to set it as the root partition once encryption is set up. Therefore, I cannot finish partitioning, because the installer won't let me move on without defining a root partition.
So it's a bit of a catch-22. Configuring the encryption removes the root partition setting, but I can't set an encrypted partition as the root partition.
Not sure if I'm missing something or if this is just some sort of bug in the installer.