I see the same failure (I think) on the fedora26 node on jenkins:
https://jenkins.isc.org/view/BIND/job/bind9-master-fedora26-64/lastCompletedBuild/testReport/bind/system/tsiggss/

this vm is a default install with only the things needed to compile bind and run jenkins installed.

~Curtis

On 9/28/17 2:49 PM, Francis Dupont via RT wrote:
> On Thu Sep 28 21:18:33 2017, muks wrote:
> > On Thu, Sep 28, 2017 at 08:54:15PM +0000, Francis Dupont via RT wrote:
> >> => it looks like it uses a system wide krb5.conf. There is no
> >> muks@ISC.ORG in the system test.
> >
> > I was kinit'd as muks@ISC.ORG, so I used kdestroy to forget it. The
> > second part of log messages in the previous message is from when
> > muks@ISC.ORG is no longer there.
>
> => it is not the config or the ccache but another thing.
> Can you check the environment variables including the defaults
> (cf https://web.mit.edu/kerberos/krb5-1.12/doc/admin/env_variables.html)
> and see if one should be (re)set. On my VM I did not install
> any Kerberos thing: I just got what is installed by default.
>
>