Localhost imap server fails after upgrade from 2.2.33.2-1 to 1:2.3.2.1

[cpblpublic+dovecot at gmail.com]

I use a localhost dovecot imap server in order to access maildir folders from Alpine (see 2009 instructions for my set up here 
https://cpbl.wordpress.com/2009/11/07/alpine-offlineimap-and-gmail-under-ubuntu/ )

My configuration has worked nicely since 2009, but failed after a recent upgrade of dovecot (during basic upgrade from Ubuntu 18.04 to 18.10).

The version of Alpine did not change. Uninstalling dovecot-core and dovecot-imapd, and reinstalling the older versions, fully fixes the problem.

I would like to know how to get my configuration working with the new version of dovecot.

Here's what the problem looks like:

I have a file auto-dovecot.conf with only the following two lines.

verbose_proctitle = yes
mail_location = maildir:/home/meuser/imap/gmailStanford:LAYOUT=fs:INBOX=/home/meuser/imap/gmailStanford/INBOX

Other /etc/ files are unchanged from installation defaults.

Alpine calls imapd when it starts, with the following command:

/usr/lib/dovecot/imap -c /home/meuser/dotfiles/auto-dovecot.conf


When I run that command, I get:

imap(meuser,)Error: net_connect_unix(/var/run/dovecot/stats-writer) failed: Permission denied
* PREAUTH [CAPABILITY IMAP4rev1 SASL-IR LOGIN-REFERRALS ID ENABLE IDLE 
SORT SORT=DISPLAY THREAD=REFERENCES THREAD=REFS THREAD=ORDEREDSUBJECT 
MULTIAPPEND URL-PARTIAL CATENATE UNSELECT CHILDREN NAMESPACE UIDPLUS 
LIST-EXTENDED I18NLEVEL=1 CONDSTORE QRESYNC ESEARCH ESORT SEARCHRES WITHIN 
CONTEXT=SEARCH LIST-STATUS BINARY MOVE SNIPPET=FUZZY LITERAL+ NOTIFY] 
Logged in as meuser




so I am guessing that the first line is the issue, since when the older version I get instead:

* PREAUTH [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE 
IDLE SORT SORT=DISPLAY THREAD=REFERENCES THREAD=REFS THREAD=ORDEREDSUBJECT 
MULTIAPPEND URL-PARTIAL CATENATE UNSELECT CHILDREN NAMESPACE UIDPLUS 
LIST-EXTENDED I18NLEVEL=1 CONDSTORE QRESYNC ESEARCH ESORT SEARCHRES WITHIN 
CONTEXT=SEARCH LIST-STATUS BINARY MOVE] Logged in as meuser


Can anyone help me? I cannot find documentation for using a localhost server for Alpine, except my own from 2009.

Many thanks!

Chris