spa -v does not show cache devices

[sdimitro]

$ sudo truncate -s 1g /tmp/dks0
$ sudo truncate -s 1g /tmp/dks1
$ sudo truncate -s 1g /tmp/dks2
$ sudo truncate -s 1g /tmp/dks3
$ sudo zpool create meta-domain raidz /tmp/dks0 /tmp/dks1 /tmp/dks2 cache /tmp/dks3
$ sudo sdb
sdb> spa -v
ADDR               NAME
------------------------------------------------------------
0xffff9f9f108f8000 meta-domain
      ADDR               STATE   AUX  DESCRIPTION
      ------------------------------------------------------------
      0xffff9f9ecf5f8000 HEALTHY NONE  root
      0xffff9f9ed6ea0000 HEALTHY NONE    raidz
      0xffff9f9ed6ea4000 HEALTHY NONE      /tmp/dks0
      0xffff9f9ed6ea8000 HEALTHY NONE      /tmp/dks1
      0xffff9f9ed9520000 HEALTHY NONE      /tmp/dks2
0xffff9f9fd3090000 rpool
      ADDR               STATE   AUX  DESCRIPTION
      ------------------------------------------------------------
      0xffff9f9fd3020000 HEALTHY NONE  root
      0xffff9f9fd2ba8000 HEALTHY NONE    /dev/sda1