Issues ISC dhcpd using libldap of OpenLDAP 2.4.48

HI!

I've tried the following without success:

Disabled Link Time Optimization (LTO), recently introduced for openSUSE
Tumbleweed, in packages openldap2 and dhcp-server. Just to make sure it
does not cause any harm.

Upstream update to dhcp 4.4.1 without any of openSUSE's back-port patches.

dhcpd does not even contact the LDAP server. It seems there's some call
into libldap failing and this is handled by dhcpd as connection error.

FWIW: I've attached the strace output of the following command which
does not say much:
LDAPNOINIT=1 /usr/sbin/dhcpd -T

I have no clues where to look now and I have to give up.

Could someone review the source of dhcpd?
The relevant files are ldap*.c:

https://source.isc.org/cgi-bin/gitweb.cgi?p=dhcp.git;a=tree;f=server

Ciao, Michael.

------------------------- dhcpd.conf ------------------------------
ldap-server "127.0.0.1";
ldap-port 389;
ldap-username "cn=host.example.com,ou=DHCP,example,dc=com";
ldap-password "host-secret";
ldap-base-dn "ou=DHCP,example,dc=com";
ldap-ssl off;
ldap-method dynamic;