Thanks to Chris Dudley for providing this information

When upgrading the developer portal additional logs can be found in /var/log/syslog and /var/log/devportal/site_action.log

The following command will print them to the screen while the upgrade is taking place.

sudo tail -F  /var/log/devportal/site_action.log /var/log/syslog

By Chris Phillips on July 20, 2017.

Canonical link

Exported from Medium on April 6, 2019.