Running bin/kerberos/experimental-kerberos-setup.sh without existing mini cluster fails with the following error after it installs required packages:
experimental-kerberos-setup.sh sources impala-config.sh, which uses testdata/cluster/admin is_kerberized to check if the cluster is kerberized. If it is not, all variables exported by minikdc_env.sh including KRB5_CONFIG are unset. The problem is that this happens even if the cluster is not yet created.
However, kerberized cluster cannot be created (via create-test-configuration.sh) without installing KDC first, so this is catch 22.