Just installed 3 Ubuntu Core images for testing on amd64 hardware. All images have the following sample repeated output on journalctl.
Jun 07 14:07:35 dedicado01 systemd[1]: Started Ubuntu Core Firstboot Configuration ttyS0.
Jun 07 14:07:35 dedicado01 systemd[1]: Stopping Serial Getty on ttyS0...
Jun 07 14:07:35 dedicado01 systemd[1]: serial-getty@ttyS0.service: Deactivated successfully.
Jun 07 14:07:35 dedicado01 systemd[1]: Stopped Serial Getty on ttyS0.
Jun 07 14:07:35 dedicado01 console-conf-write-login-details[25510]: i18n file is /usr/share/subiquity/subiquitycore/i18n.py
Jun 07 14:07:35 dedicado01 console-conf-write-login-details[25510]: Final localedir is /usr/share/locale
Jun 07 14:07:35 dedicado01 console-conf-write-login-details[25510]: switch_language en_US
Jun 07 14:07:35 dedicado01 systemd[1]: Started Getty on tty1.
Jun 07 14:07:35 dedicado01 systemd[1]: console-conf@tty1.service: Deactivated successfully.
Jun 07 14:07:35 dedicado01 systemd[1]: console-conf@tty1.service: Scheduled restart job, restart counter is at 429.
Jun 07 14:07:35 dedicado01 systemd[1]: Stopped Ubuntu Core Firstboot Configuration tty1.
Jun 07 14:07:35 dedicado01 systemd[1]: Started Ubuntu Core Firstboot Configuration tty1.
Jun 07 14:07:35 dedicado01 systemd[1]: Stopping Getty on tty1...
Jun 07 14:07:35 dedicado01 systemd[1]: getty@tty1.service: Deactivated successfully.
Jun 07 14:07:35 dedicado01 systemd[1]: Stopped Getty on tty1.
Jun 07 14:07:35 dedicado01 console-conf-write-login-details[25537]: i18n file is /usr/share/subiquity/subiquitycore/i18n.py
Jun 07 14:07:35 dedicado01 console-conf-write-login-details[25537]: Final localedir is /usr/share/locale
Jun 07 14:07:35 dedicado01 console-conf-write-login-details[25537]: switch_language en_US
Jun 07 14:07:40 dedicado01 systemd[1]: Started Serial Getty on ttyS0.
Jun 07 14:07:40 dedicado01 systemd[1]: serial-console-conf@ttyS0.service: Deactivated successfully.
Jun 07 14:07:40 dedicado01 systemd[1]: serial-console-conf@ttyS0.service: Scheduled restart job, restart counter is at 438.
Jun 07 14:07:40 dedicado01 systemd[1]: Stopped Ubuntu Core Firstboot Configuration ttyS0.
Jun 07 14:07:40 dedicado01 systemd[1]: Started Ubuntu Core Firstboot Configuration ttyS0.
Jun 07 14:07:40 dedicado01 systemd[1]: Stopping Serial Getty on ttyS0...
Jun 07 14:07:40 dedicado01 systemd[1]: serial-getty@ttyS0.service: Deactivated successfully.
Jun 07 14:07:40 dedicado01 systemd[1]: Stopped Serial Getty on ttyS0.
Jun 07 14:07:40 dedicado01 console-conf-write-login-details[25564]: i18n file is /usr/share/subiquity/subiquitycore/i18n.py
Jun 07 14:07:40 dedicado01 console-conf-write-login-details[25564]: Final localedir is /usr/share/locale
Jun 07 14:07:40 dedicado01 console-conf-write-login-details[25564]: switch_language en_US
Jun 07 14:07:41 dedicado01 systemd[1]: Started Getty on tty1.
Jun 07 14:07:41 dedicado01 systemd[1]: console-conf@tty1.service: Deactivated successfully.
Jun 07 14:07:41 dedicado01 systemd[1]: console-conf@tty1.service: Scheduled restart job, restart counter is at 430.
Jun 07 14:07:41 dedicado01 systemd[1]: Stopped Ubuntu Core Firstboot Configuration tty1.
Jun 07 14:07:41 dedicado01 systemd[1]: Started Ubuntu Core Firstboot Configuration tty1.
Jun 07 14:07:41 dedicado01 systemd[1]: Stopping Getty on tty1...
Jun 07 14:07:41 dedicado01 systemd[1]: getty@tty1.service: Deactivated successfully.
Jun 07 14:07:41 dedicado01 systemd[1]: Stopped Getty on tty1.
Jun 07 14:07:41 dedicado01 console-conf-write-login-details[25592]: i18n file is /usr/share/subiquity/subiquitycore/i18n.py
Jun 07 14:07:41 dedicado01 console-conf-write-login-details[25592]: Final localedir is /usr/share/locale
Jun 07 14:07:41 dedicado01 console-conf-write-login-details[25592]: switch_language en_US
Jun 07 14:07:45 dedicado01 systemd[1]: Started Serial Getty on ttyS0.
Jun 07 14:07:45 dedicado01 systemd[1]: serial-console-conf@ttyS0.service: Deactivated successfully.
Jun 07 14:07:45 dedicado01 systemd[1]: serial-console-conf@ttyS0.service: Scheduled restart job, restart counter is at 439.
Jun 07 14:07:45 dedicado01 systemd[1]: Stopped Ubuntu Core Firstboot Configuration ttyS0.
Jun 07 14:07:45 dedicado01 systemd[1]: Started Ubuntu Core Firstboot Configuration ttyS0.
Jun 07 14:07:45 dedicado01 systemd[1]: Stopping Serial Getty on ttyS0...
Jun 07 14:07:45 dedicado01 systemd[1]: serial-getty@ttyS0.service: Deactivated successfully.
Jun 07 14:07:45 dedicado01 systemd[1]: Stopped Serial Getty on ttyS0.
Jun 07 14:07:46 dedicado01 console-conf-write-login-details[25619]: i18n file is /usr/share/subiquity/subiquitycore/i18n.py
Jun 07 14:07:46 dedicado01 console-conf-write-login-details[25619]: Final localedir is /usr/share/locale
Jun 07 14:07:46 dedicado01 console-conf-write-login-details[25619]: switch_language en_US
Did anyone else encounter a similar issue? Can someone help me debug this?