Where does the debugging message come from?

Hello- I'm testing out some local mods I've made to the ldapsearch command and I have the -d 2 flag to enable debugging set. /usr/local/src/openldap/openldap-2.4.46/clients/tools/ldapsearch -h ldap-test1.test.org -p 11389 -ZZ -D cn=somecn -w somepw -b 'dc=test,dc=org' '(uid=husk)' -d 2 When I run this, I get a lot of what I need, but I noticed the following is emitted at the top. *Using CA cert /etc/openldap/cacerts/ca-bundle.crt as stipulated by environment variable $LDAPTLS_CACERT.* I was looking to see where in the openldap code this string comes from, but I can't seem to find it. (I thought a thorough 'grepping' would locate it, but it did not, nor does strings /usr/local/src/openldap/openldap-2.4.46/clients/tools/ldapsearch |grep "stipulated" ). So it's from the ssl library I assumed. Nope, didn't find it there either. Can someone point me to where it comes from please? Sorry if this is a dumb question that I should already know.