Comment 7 for bug 1858802

Test Steps:
---

# Document versions
lsb_release -cs
uname -rv
dpkg -s bcache-tools xfsprogs | grep -i version

# Create disk image
DISK_IMG=disk.img
rm -f $DISK_IMG
dd if=/dev/zero of=$DISK_IMG bs=1G count=0 seek=1

# Create bcache backing device from disk image
BACKING_DEV=$(sudo losetup --find --show $DISK_IMG)
sudo make-bcache -B $BACKING_DEV
echo $BACKING_DEV | sudo tee /sys/fs/bcache/register # for Disco only.
sleep 1

# Create xfs on its bcache device
BCACHE_DEV="$(readlink -e /sys/block/$(basename $BACKING_DEV)/bcache/dev)"
BCACHE_DEV="/dev/$(basename $BCACHE_DEV)"
sudo mkfs.xfs -d agsize=16m -l agnum=0 -f $BCACHE_DEV
sleep 1

# Stop bcache device to flush (needed)
echo 1 | sudo tee /sys/block/$(basename $BCACHE_DEV)/bcache/stop
sleep 1

# Check signatures for XFS and XFS journal (both before 0x40000 / 256K)
sudo hexdump -C $BACKING_DEV | grep -m2 -e XFSB -e 'fe ed ba be'

# Test old version
dpkg -s libblkid1 | grep -i version
sudo blkid -o udev -p $BACKING_DEV

# Install new version
sudo add-apt-repository ppa:mfo/lp1858802-sru
sudo apt update
sudo apt install -y libblkid1

# Test new version
dpkg -s libblkid1 | grep -i version
sudo blkid -o udev -p $BACKING_DEV

# Stop loop/backing device
sudo losetup -d $BACKING_DEV