session optional            pam_mkhomedir.so skel=/etc/skel/ umask=0077
# end of pam-auth-update config

#id ad.test.edu\test
 id: ‘ad.test.edu\test’: no such user

$grep -i  ad.te /etc/krb5.conf
    kdc = ad.test.edu
    admin_server = ad.test.edu

$kinit test@AD.TEST.EDU
 Password for test@AD.TEST.EDU:

$klist
 Ticket cache: FILE:/tmp/krb5cc_1000
 Default principal: test@AD.TEST.EDU

   Valid starting       Expires              Service principal
   03/20/2019 16:36:05  03/21/2019 02:36:05
 krbtgt/AD.TEST.EDU@AD.TEST.EDU

Mar 20 10:09:58 TEST lightdm: pam_krb5(lightdm:auth): user test@AD.TEST.EDU authenticated as test@AD.TEST.EDU
Mar 20 10:09:58 TEST  lightdm: gkr-pam: error looking up user information
Mar 20 10:09:58 TEST  lightdm: pam_kwallet5(lightdm:auth): (null): pam_sm_authenticate
Mar 20 10:09:58 TEST  lightdm: pam_kwallet5(lightdm:auth): pam_kwallet5: Couldn't get user info (passwd) info
Mar 20 10:09:58 TEST  lightdm: pam_unix(lightdm:account): could not identify user (from getpwnam(test@AD.TEST.EDU))
Mar 20 10:09:58 TEST  lightdm: PAM unable to dlopen(pam_kwallet.so): /lib/security/pam_kwallet.so: cannot open shared object file: No such file or directory
Mar 20 10:09:58 TEST  lightdm: PAM adding faulty module: pam_kwallet.so

Mar 20 10:09:58 TEST lightdm: PAM unable to dlopen(pam_kwallet.so): /lib/security/pam_kwallet.so: cannot open shared object file: No such file or directory

Mar 20 10:14:35 TEST lightdm: pam_krb5(lightdm:auth): user test@AD.TEST.EDU authenticated as test@AD.TEST.EDU
Mar 20 10:14:35 TEST lightdm: gkr-pam: error looking up user information
Mar 20 10:14:35 TEST lightdm: pam_kwallet(lightdm:auth): (null): pam_sm_authenticate
Mar 20 10:14:35 TEST lightdm: pam_kwallet(lightdm:auth): pam_kwallet: Couldn't get user info (passwd) info
Mar 20 10:14:35 TEST lightdm: pam_kwallet5(lightdm:auth): (null): pam_sm_authenticate
Mar 20 10:14:35 TEST lightdm: pam_kwallet5(lightdm:auth): pam_kwallet5: Couldn't get user info (passwd) info
Mar 20 10:14:35 TEST lightdm: pam_unix(lightdm:account): could not identify user (from getpwnam(test@AD.TEST.EDU))