Why Does 'Passwd' Fail to Change User's Pw [Duplicate]

** Term-control chars edited out:

Script started on 2017-12-01 06:51:43-0500
/etc/bash.bashrc
~root/.bashrc
declare -x PATH="/root/sbin:/usr/local/sbin:/usr/sbin:/sbin:/root/bin:/root/.emacs.d/term-cmd:/usr/local/bin:/usr/bin:/bin:/snap/bin:/root/Scripts"
declare -x HOME="/root"

bash # passwd bunky

Current Kerberos password: 

New password: 

Retype new password: 

Current Kerberos password: 

Current password: 

passwd: Authentication token manipulation error

passwd: password unchanged


bash exit
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1) I have never set up Kerberos. Why is passwd asking for "Current Kerberos password?

2) As root, I should not require to know 's "current password".

3) In fact, an unknown problem with the user's old password is the reason for the whole exercise.