How to install xfs_scrub

Hi!
When i do xfstests with ext4 fs, one case fail as below:

FSTYP         -- ext4
PLATFORM      -- Linux/x86_64 local 4.13.0-rc3
MKFS_OPTIONS  -- /dev/sda8
MOUNT_OPTIONS -- -o acl,user_xattr /dev/sda8 /fs/scratch 

ext4/023         [not run] xfs_scrub not found <===
Not run: ext4/023
Passed all 0 tests

It is clear that i do not have xfs_scrub cmd.
I have read related docs but do not find where or how can i get it.
I use v4.7 xfsprogs and xfstests commit is a00c51a0.
Could you help me?

Thanks

Xiang