freebsd stable - Feb 2007 - problems with portupgrade under non-root user

I want to set up a FreeBSD system so that all portupgrades are done by a 
"portbld" user, which has restricted 'sudo' rights to execute
only
portupgrade-related commands. To that end, I did the following:

$ sudo chown -R portbld:portbld /usr/ports
$ sudo chown -R portbld:portbld /var/db/sup/ports-all
$ cd /usr/ports && sudo -u portbld make update
(cvsup runs)
(add 'portbld' to sudoers with NOPASSWD: ALL for now)
$ sudo -u portbld portupgrade -s dovecot

Unfortunately this last step doesn't work: ruby dumps core:

Making all in doc
cat dovecot-config.in|sed
"s|moduledir=|moduledir=/usr/local/lib/dovecot|"
> dovecot-config
** Listing the failed packages (*:skipped / !:failed)
         ! mail/dovecot (dovecot-1.0.r22)        (Permission denied)
--->  Packages processed: 0 done, 0 ignored, 0 skipped and 1 failed
/usr/local/sbin/portupgrade:2084: [BUG] Segmentation fault
ruby 1.8.5 (2006-12-25) [i386-freebsd6]

Abort trap: 6 (core dumped)


Any ideas here?

- Julian

[ Julian C. Dunn <jdunn@aquezada.com>  *  "You can throw confetti,  
]
[ WWW: www.aquezada.com/staff/julian   *  but you're still going     ]
[ PGP: 91B3 7A9D 683C 7C16 715F        *  through the motions, baby" ]
[      442C 6065 D533 FDC2 05B9        *                - Aimee Mann ]

Julian C. Dunn wrote:
> I want to set up a FreeBSD system so that all portupgrades are done by a
> "portbld" user, which has restricted 'sudo' rights to
execute only
> portupgrade-related commands. To that end, I did the following:
> 
> $ sudo chown -R portbld:portbld /usr/ports
> $ sudo chown -R portbld:portbld /var/db/sup/ports-all
> $ cd /usr/ports && sudo -u portbld make update
> (cvsup runs)
> (add 'portbld' to sudoers with NOPASSWD: ALL for now)
> $ sudo -u portbld portupgrade -s dovecot
You need root at least for port install.
> 
> Unfortunately this last step doesn't work: ruby dumps core:
> 
> Making all in doc
> cat dovecot-config.in|sed
"s|moduledir=|moduledir=/usr/local/lib/dovecot|"
>> dovecot-config
> ** Listing the failed packages (*:skipped / !:failed)
>         ! mail/dovecot (dovecot-1.0.r22)        (Permission denied)
> --->  Packages processed: 0 done, 0 ignored, 0 skipped and 1 failed
> /usr/local/sbin/portupgrade:2084: [BUG] Segmentation fault
> ruby 1.8.5 (2006-12-25) [i386-freebsd6]
> 
> Abort trap: 6 (core dumped)
/var/db/pkg and var/db/ports must be writable for the user too.

-- 
Dixi.
Sem.