OK, I have captured both: $ pstree -al
During the first occasion: `-aptitude safe-upgrade |-sh -c /usr/sbin/dpkg-preconfigure --apt || true | `-dpkg-preconfigu -w /usr/sbin/dpkg-preconfigure --apt | |-(dpkg-preconfigu) | |-keyboard-config /tmp/keyboard-configuration.config.BvbEEk configure 1.150 | `-whiptail --backtitle Package configuration --title Configuring keyboard-configuration --output-fd 12 --default-item Generic 105-key (Intl) PC --menu Please select the model of the keyboard of this machine.\012\012Keyboard m During the second occasion: `-aptitude safe-upgrade |-dpkg --status-fd 38 --no-triggers --configure --pending | `-frontend -w /usr/share/debconf/frontend /var/lib/dpkg/info/keyboard-configuration.postinst configure 1.150 | |-keyboard-config /var/lib/dpkg/info/keyboard-configuration.config configure 1.150 | `-whiptail --backtitle Package configuration --title Configuring keyboard-configuration --output-fd 11 --default-item Generic 105-key (Intl) PC --menu Please select the model of the keyboard of this machine.\012\01 They only happen a few minutes apart, during upgrade.