Can't use the go piugin and specify a go-channel

Hey,

according to the documentation you can specify a snap channel for go, so that it doesn’t use your systems (non-snap) package manager. All you have to do is add go-channel to the plugin.

So i ended up with this:

name: cordless
version: git
summary: Third party discord client
description: |
  A third party discord client for your terminal.

confinement: strict
grade: stable

base: core18

parts:
  cordless:
    source: .
    plugin: go
    go-channel: "1.12/stable"
    go-importpath: github.com/Bios-Marcel/cordless
    stage-packages:
      - xclip

apps:
  cordless:
    command: bin/cordless
    plugs: [x11, network-bind]
    environment:
      XDG_CONFIG_DIR: $SNAP_USER_DATA/

However, when running snapcraft, I get this:

Failed to load plugin: properties failed to load for go: Additional properties are not allowed (‘go-channel’ was unexpected)

I don’t know why this happens, but I have even seen people using this feature. Sadly there is no up-to-date example in the documentation either. I am on ubuntu 19.04 and have the latest version of snap that’s on the apt-repositories.

Can anyone tell me what I am missing here?

regards

Marcel