Comment 13 for bug 1265192

command line option at boot: debug-ubiquity
edited /bin/partman to contain set -x
started ubiquity with ubiquity -d
chose erase existing lubuntu and reinstall

previous partition layout: sda1: 4G / ; sda2 2G /home
new layout : sda1 4G / ; sda5 2G swap

logs:

/var/log/installer
/var/log/partman
/var/log/syslog