Comment 10 for bug 1673605

I ran the test again. This time, I did get a /var directory under @ on the partition, but it's empty. /usr and /lib are populated; I can get a full file list if necessary, but it's very long, unlike the previous install. The preseed in use is here:
http://bazaar.launchpad.net/~ubuntu-test-case-dev/ubuntu-test-cases/desktop/view/head:/preseeds/default_btrfs.cfg
The only difference between that and the preseed here that works:
http://bazaar.launchpad.net/~ubuntu-test-case-dev/ubuntu-test-cases/desktop/view/head:/preseeds/default.cfg
is this line:
d-i partman/default_filesystem string btrfs