Hi Joseph,
Yes, you do need to set the environment variable KRB5_CONFIG in order
to have kerberos access.
More, according to MIT documentation, you can set several file names
in this. Please refer to Kerberos documentation.
MIT Kerberos Documentation
KRB5_CONFIG
Specifies the location of the Kerberos configuration file. The default
is SYSCONFDIR/krb5.conf. Multiple filenames can be specified,
separated by a colon; all files which are present will be read.
https://web.mit.edu/kerberos/krb5-latest/doc/user/user_config/kerberos.html#kerberos-7
I hope this helps,
Best Regards,
Patrick