I'm trying to build a custom Ubuntu Core image for my Raspberry Pi 3 (with preinstalled snaps) and I know that this is not yet supported.
I thought I could try the ubuntu-device-flash tool anyways (I found this and this, and the pi3 oem snap).
The second page suggests installing ubuntu-device-flash as a snap, using
$ sudo snap install --channel=edge --devmode ubuntu-device-flash
but on my Ubuntu 16.04 server this gives me
error: cannot install "ubuntu-device-flash": snap not found
Am I missing something?