Hi, I'm working on a bug (#818687) that pre-dates Jessie's release, and I'd like to get it resolve it before Stretch goes into freeze. En résumé it's a rename of btrfs-tools to btrfs-progs, and this affects debian-installer. I imagine that a patch can be generated with a simple substitution of btrfs-progs for btrfs-tools. Please take a look at it and let me know what I can do to help. Sincerely, Nicholas