Postfix/verify_cache.db out of chroot

Hello.

I am going to report as follows.

There are some entries in /var/log/mail.log, like
postfix/verify[9771]: close database /var/lib/postfix/verify_cache.db: No such file or directory (possible Berkeley DB bug)

Though default configulation of /etc/postfix/master.cf on verify is
verify unix - - - - 1 verify

 /var/lib/postfix/verify_cache.db is not in chroot directory (/var/spool/postfix).

For the sake of apt-get upgrade destroying my postfix,

Fix the verify_cache.db file into /var/spool/postfix directory. please.

Thank You.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: postfix 2.11.0-1ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-49.83-generic 3.13.11-ckt17
Uname: Linux 3.13.0-49-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.10
Architecture: amd64
Date: Mon May 11 18:47:42 2015
EtcMailname: valinux.co.jp
ExecutablePath: /usr/lib/postfix/verify
Hostname: va-mail.local.valinux.co.jp
PostconfMydomain: valinux.co.jp
PostconfMyhostname: mail.valinux.co.jp
PostconfMyorigin: /etc/mailname
ProcEnviron: LANG=C
ResolvConf:
 # Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
 # DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
 nameserver 172.18.1.10
 search valinux.co.jp local.valinux.co.jp
SourcePackage: postfix
UpgradeStatus: No upgrade log present (probably fresh install)