Unable to rebuild app: not supported docker storage driver (btrfs)

Product Support Self-hosting
2

Note

Both overlay and overlay2 are currently unsupported on btrfs or any Copy on Write filesystem and should only be used over ext4 partitions.

As Docker doesn’t support using the overlay2 driver on top of btrfs, it looks like the recommendation from the launcher tool is the extent of your options here. That is, continue running Discourse on a system where Docker is backed by ext4 or modify launcher to ignore the storage driver and hope for the best.

Commenting out (prepending # to) the exit 1 line in the following lines of the launcher script with your preferred text editor will achieve the latter if you want to take that route:

Considering “Other storage drivers are known to be problematic” though, I wouldn’t recommend doing that.