upgrade from trisquel mini taranis 4 to trisquel mini slaine 4.5

Have you checked the Updates tab in "Software Sources" (software-properties-gtk), at the Release upgrade, to be set on "Normal releases" ?
And then you can:
sudo apt-get update && sudo apt-get upgrade

I think you meant

sudo apt-get update && sudo apt-get dist-upgrade

If you are looking to do a complete OS upgrade.

Many thanks for your replies.

In fact, I use aptitude, and aptitude full-upgrade simply upgrade Taranis.

I was expecting the update manager to react and let me know a dist-upgrade was available but it didn't.

What I have decided to try is change taranis for slaine in /etc/apt/sources.list, move to a tty and sudo aptitude update && aptitude full-upgrade.

This seems to have done the job except that I have kernel 2.6.32.33 on this Mini Trisquel instead of 2.6.35-30 on Trisquel Slaine Gnome. Maybe that's because I chose not to update grub during upgrade because I didn't want to erase my custom file.

I have installed the latest generic kernel from Synaptic and rebooted. The first kernel on the GRUB screen is -virtual and the second is -generic but Synaptic installed both when I chose to install linux-image…-generic.

Yet, this method is rather unorthodox, rather too close to Debian rolling release method.

And I haven't tested this fancifully-acquired Slaine enough to be sure it works without a hitch.