I'm concerned with the "EXPIRATION_DATE=2022-06-30" below:
FreeBSD 12.3 base contains /usr/include/db.h without DB_VERSION_STRING
with
* @(#)db.h 8.7 (Berkeley) 6/16/94
* $FreeBSD: releng/12.3/include/db.h 326024 2017-11-20 19:45:28Z pfg $
Ports have:
databases/db18:
PORTVERSION= 18.1.40
COMMENT= Oracle Berkeley DB, Release ${BDBVER}
databases/db5:
PORTVERSION= 5.3.28
DEPRECATED= EOLd, potential security issues, maybe use db18 instead
EXPIRATION_DATE=2022-06-30
COMMENT= Oracle Berkeley DB, revision ${BDBVER}
Exim 4.96 src/hintsdb.h :
# include <db.h>
/* 1.x did no locking
2.x had facilities, but exim does it's own
3.x+ unknown
*/
/* We can distinguish between versions 1.x and 2.x/3.x by looking for a
definition of DB_VERSION_STRING, which is present in versions 2.x onwards. */
# ifdef DB_VERSION_STRING
# if DB_VERSION_MAJOR >= 6
# error Version 6 and later BDB API is not supported