[Dovecot] Maildir permissions and Solr re-indexing

[Michael Welsh Duggan]

I am running a very small dovecot installation with only one user (me).
I use the Solr indexer for indexing.  Due to complicated reasons, I was
forced to remove all the indexes and need to re-index everything.

All the files in my Maildir are owned by md5i:mail (I am md5i), and have
660 permissions.  All directories have the same user:group permissions,
and 770 with the setguid bit set.  (That last may not be necessary, but
I was trying several things to get my use case to work.)

Unfortunately, I can't seem to get re-indexing to work.  When I do
"doveadm fts rescan -A" as root, I get the following error for each of my
subgroups:

doveadm(md5i): Error: fchown(/home/md5i/Maildir/.mail.test/dovecot.index.log.newlock, group=8(mail)) failed: Operation not permitted (egid=1000(md5i), group based on /home/md5i/Maildir/.mail.test - see http://wiki2.dovecot.org/Errors/ChgrpNoPerm)

After this, each directory has a dovecot.index.log with md5i:md5i 600
permissions. 

I've read the mentioned page, and played around with the ideas on it,
but haven't gotten things to work.  Anyone have any clue to ship my way?

-- 
Michael Welsh Duggan
(md5i at md5i.com)