Comment 3 for bug 1427264

This issue is not specific to eCryptfs. It is specific to a user's home directory being a mount point. For example, I can reproduce this issue with ext4:

foo@sec-vivid-amd64:~$ grep home\/foo /proc/mounts
/dev/loop0 /home/foo ext4 rw,relatime,data=ordered 0 0
foo@sec-vivid-amd64:~$ schroot -c click-amd64 -- true
E: 10mount: umount: /var/lib/schroot/mount/click-amd64-63d79a95-7c79-4f59-97ea-c9089e9c0c9f/home/foo: target is busy
E: 10mount: (In some cases useful info about processes that
E: click-amd64-63d79a95-7c79-4f59-97ea-c9089e9c0c9f: Chroot setup failed: stage=setup-stop
foo@sec-vivid-amd64:~$ grep home\/foo /proc/mounts
/dev/loop0 /home/foo ext4 rw,relatime,data=ordered 0 0
/dev/loop0 /var/lib/schroot/mount/click-amd64-63d79a95-7c79-4f59-97ea-c9089e9c0c9f/home/foo ext4 rw,relatime,data=ordered 0 0