Hi, this is being tracked on LP: #1817300.
It only affects snaps using classic confinement, fix should be available everywhere in the coming days, this is where it currently works:
- snapcraft from edge
- launchpad/build.snapcraft.io
There was a bootstrapping issue as this affected snapcraft from building itself as well.
You can try and see if the fix works for docker by creating an image using edge.Dockerfile by following the documentation on https://github.com/snapcore/snapcraft/tree/master/docker