ERROR: Element 'sysctl' not found in '

[qiweichao]

1.environment:octavia package, diskimage-builder

2.destination:make a amphora-x64-haproxy.qcow2 image

3.step:
      (1) cd /octavia/diskimage-create/
      (2) yum install diskimage-builder
      (3) ./diskimage-create.sh

4. error:Building elements: base base vm ubuntu-minimal pip-and-virtualenv haproxy-octavia rebind-sshd no-resolvconf amphora-agent sos keepalived-octavia ipvsadmin pip-cache certs-ramfs
ERROR: Element 'sysctl' not found in '/home/octavia/octavia/elements:/usr/bin/../share/diskimage-builder/elements'

In addition,There is no sysctl element in the octavia and diskimage-builder package elements directory.so how to get sysctl element ? Maybe install another version of diskimage-builder?

The last, I hope to get yours as soon as possible,thanks!