Comment 1 for bug 2045317

The issue is that the loki-k8s charm in edge/325 only supports 20.04 (focal). There's no jammy support.

This overlay works

applications:
  loki:
    channel: edge/325
    arch: amd64
    base: ubuntu@20.04
    options:
    ingestion-rate-mb: 60
    ingestion-burst-size-mb: 100
    resources:
      loki-image: ubuntu/loki:2.8.4-22.04

The error message could be better. The response from charmhub does include the supported bases so that should be surfaced to let the user know how to correct the problem.