v2.11.1 coredump, 'signal 6', BT provided

On,

    lsb_release -rd
        Description:    openSUSE Leap 15.0
        Release:        15.0
    uname -rm
        4.18.12-lp150.3.ga880bd8-default x86_64

I've built & run,

    /usr/local/opendkim/sbin/opendkim -V
        opendkim: OpenDKIM Filter v2.11.0
                Compiled with OpenSSL 1.1.1  11 Sep 2018
                SMFI_VERSION 0x1000001
                libmilter version 1.0.1
                Supported signing algorithms:
                        rsa-sha1
                        rsa-sha256
                        ed25519-sha256
                Supported canonicalization algorithms:
                        relaxed
                        simple
                Active code options:
                        USE_MDB
                        USE_UNBOUND
                        _FFR_DIFFHEADERS
                        _FFR_STATS
                        _FFR_VBR
                libopendkim 2.11.0: diffheaders debug

Once launched, it runs for a fair while, accepting/verifying submitted msgs, then intermittenly terminates with signal 6,

    journalctl -f | grep -i opendkim
        ...
        Oct 08 11:54:03 mail.loc systemd[1]: Starting OpenDKIM...
        Oct 08 11:54:03 mail.loc systemd[1]: Started OpenDKIM.
        Oct 08 11:54:03 mail.loc opendkim[44544]: OpenDKIM Filter: Opening listen socket on conn local:/var/run/opendkim/opendkim.sock
        Oct 08 11:54:03 mail.loc opendkim[44544]: OpenDKIM Filter v2.11.0 starting (args: -l -x /usr/local/etc/opendkim/opendkim.conf -u opendkim)
        ...
        Oct 08 13:39:16 mail.loc opendkim[44576]: 42TXK023bYz10hm: DKIM-Signature field added (s=dkim-7f99436557929e03, d=example.com)
        Oct 08 13:39:16 mail.loc opendkim[44543]: terminated with signal 6, restarting
        Oct 08 13:39:16 mail.loc opendkim[49996]: OpenDKIM Filter: Opening listen socket on conn local:/var/run/opendkim/opendkim.sock
        Oct 08 13:39:16 mail.loc opendkim[49996]: OpenDKIM Filter v2.11.0 starting (args: -l -x /usr/local/etc/opendkim/opendkim.conf -u opendkim)
        ...

Core dumps

    ls -al /var/lib/systemd/coredump/core*
        -rw------- 1 opendkim postfix-milter 39M Oct  8 13:39 /var/lib/systemd/coredump/core.44576

and a backtrace reports,

    gdb /usr/local/opendkim/sbin/opendkim /var/lib/systemd/coredump/core.44576
        GNU gdb (GDB; openSUSE Leap 15.0) 8.1
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        Reading symbols from /usr/local/opendkim/sbin/opendkim...done.
        [New LWP 49990]
        [New LWP 44576]
        [New LWP 44577]
        [New LWP 48292]
        [New LWP 44578]
        [Thread debugging using libthread_db enabled]
        Using host libthread_db library "/lib64/libthread_db.so.1".
        Core was generated by `/usr/local/opendkim/sbin/opendkim -l -x /usr/local/etc/opendkim/opendkim.conf -'.
        Program terminated with signal SIGABRT, Aborted.
        #0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51
        51      ../sysdeps/unix/sysv/linux/raise.c: No such file or directory.
        [Current thread is 1 (Thread 0x7f6c460a3700 (LWP 49990))]
        (gdb) print p
        No symbol "p" in current context.
        (gdb) bt
            #0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51
            #1  0x00007f6c492336c1 in __GI_abort () at abort.c:79
            #2  0x00007f6c49275427 in __libc_message (action=action@entry=(do_abort | do_backtrace),
                fmt=fmt@entry=0x7f6c4937e230 "*** Error in `%s': %s: 0x%s ***\n")
                at ../sysdeps/posix/libc_fatal.c:181
            #3  0x00007f6c4927bc43 in malloc_printerr (action=<optimized out>,
                str=0x7f6c4937e5b8 "double free or corruption (out)", ptr=<optimized out>,
                ar_ptr=<optimized out>) at malloc.c:5428
            #4  0x00007f6c4927d549 in _int_free (av=0x7f6c495b0c20 <main_arena>, p=<optimized out>,
                have_lock=<optimized out>) at malloc.c:4170
            #5  0x00007f6c4936260b in tcache_thread_freeres () at malloc.c:2999
            #6  0x00007f6c49362662 in __libc_thread_freeres () at thread-freeres.c:29
            #7  0x00007f6c495bd57e in start_thread (arg=0x7f6c460a3700) at pthread_create.c:478
            #8  0x00007f6c492f482f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95