Everything goes well up to a certain point. In step "4. Configure DB connection", a world-writable database file is selected and connection is tested OK. On step "7. Install", we save the configuration file and press "Retry", at which point PHP dies. From /var/log/apache2/error.log: [notice] child pid 32249 exit signal Segmentation fault (11).

For simplicity, it might also be a good idea to disable "Host", "User", and "Password" fields during step "4. Configure DB connection" when SQLite3 is selected.