Snaps installing into /root

I’ve been testing a snap using snap try prime.
I’ve installed/uninstalled it many times and the path I see it install into is

I’ve just removed and then snap try the snap once more to find that the snaps root is now:
/root/snap rather than /snap

I’ve just had a look and it looks like I have a mix of snaps
sudo ls /root/snap
snapcraft tomcat-with-ssl tomcat-with-ssl-snap

sudo ls /snap
bin  core  README  snapcraft  tomcat-with-ssl

When I tried to remove one of the /root/snaps

sudo -i
root@test-2:~# snap remove tomcat-with-ssl-snap
snap "tomcat-with-ssl-snap" is not installed

What created the /root/snap directory?
Why is my ‘try’ sudden pathing in /root/snap?

snap --version
snap 2.31
snapd 2.31
series 16
ubuntu 16.04
kernel 4.4.0-87-generic

So I think I can answer my own question.

So the issue is that SNAP_USER_DATA points to

which I wasn’t expecting, but I assume is normal behaviour.

I’m now guessing that when I do a snap remove that is not cleaning up data in SNAP_USER_DATA.

I had also changed my pathing to SNAP_USER_DATA and I guess I hadn’t notice the path change.

So I think it was just me being stupid.

For the record: