Troubleshooting

Documentation / Contents - CyLogin

• Overview of CyLogin
  • What It Is
  • What It Is Not
  • The Programs
  • In This Book
• Setting Up
  • What You Need
  • Build and Install
  • Enable With the Helper
  • Linux SysV and systemd
  • NetBSD rc.d
  • PAM Service File
  • Xservers and VT
  • Headless and LXC
  • Competing Display Managers
  • Check That It Works
  • Disable and Rollback
  • Common Mistakes
• Using CyLogin
  • Logging In
  • Faces
  • noiconlogin
  • Session Lock
  • Autologin and Classroom
  • After Login (Session)
  • Failsafe
• Configuration
  • Master Conf
  • Appearance
  • Session Path
  • Unsafe Knobs
  • Autologin Knobs
  • Lock Timeout
  • Classroom Sample
• Enable and Disable Helpers
  • cylogin-enable
  • Every enable Flag
  • cylogin-disable
  • Examples
• Security and PAM
  • Defaults
  • PAM Stacks
  • Empty Password Gate
  • Auth Dir and Cookies
  • Vs XDM and login
  • Lab Matrix
• Command Line
  • cylogind
  • cylogin Greeter
  • cylogin-authcheck
  • cychooser
• Keys and Shortcuts
• Files and Paths
  • System Conf
  • Runtime
  • Share Install
  • Init and PAM
• Troubleshooting
  • Greeter Never Appears
  • No Screens Found
  • PAM Failures
  • Wrong Session After Login
  • Setuid and Nobody
• Copyright

Troubleshooting

Setup checklist is in Setting Up. Security and PAM detail is in Security and PAM.

Greeter Never Appears

1. Is cylogind running? pgrep -a cylogind 2. Is Xorg running for :0? pgrep -a Xorg; check /var/log/Xorg.0.log 3. Did cylogind give up after four X start attempts? journalctl -u cylogind or syslog; look for "giving up on :0" 4. Is a competing DM still owning the seat? systemctl status lightdm 5. Re-run: sudo cylogin-enable --dry-run then fix what it warns about

If X never becomes ready, the greeter never starts. Fix X first.

No Screens Found

Xorg log shows Fatal server error: no screens found. Common on unprivileged LXC: no /dev/dri, /dev/fb0, or /dev/tty0.

• Install xserver-xorg-video-dummy (Debian) or xorg-x11-drv-dummy (RHEL)
• sudo cylogin-enable --seed-conf --force-conf
• Start again (or cylogin-enable --yes)

Enable skips start when there is no seat and no dummy_drv.so, so you should not see a respawn storm from a current helper. If an old cylogind is already looping, stop it:

sudo /etc/init.d/cylogind stop
# or: sudo systemctl stop cylogind

PAM Failures

• Missing /etc/pam.d/cylogin on a --with-pam build: install with cylogin-enable --install-pam
• Wrong stack for the OS: use --force-pam after confirming the sample (Debian vs RHEL files under share/cylogin)
• Good password refused: check nologin, expiry, home, allow_root_login
• Empty password unexpectedly accepted: should not happen with defaults; confirm allow_null_passwd is off and you are on current auth.c

Lab: tools/cylogin-pam-matrix.sh should report FAILS=0.

Wrong Session After Login

You land in icewm/Slim leftovers instead of Cyanotype:

• Set session /usr/local/bin/startcyanotype.sh in cylogin.conf (classroom sample does this)
• Or remove/rename ~/.xsession, or only honour it with CYLOGIN_USER_XSESSION=1
• Read /etc/cyanotype/Xsession and ~/.xsession-errors

Setuid and Nobody

ls -l /usr/local/bin/cylogin-authcheck
# expect -rwsr-xr-x root root   (or root wheel on BSD)

sudo cylogin-enable --fix-privs

Greeter should show as user nobody in ps. If it runs as root, conf greeter_user is wrong or the daemon could not drop. getent passwd nobody must succeed; helpers warn if it does not. Do not create _cylogin unless you have an explicit product decision to do so.

Still Stuck

• man cylogind / man cylogin
• share/cylogin/README.md
• docs/punchlists/CYLOGIN-ENABLE.md test log
• Snapshot rollback on lab CTs: pct rollback to pre-cylogin-* or golden