- [ ] Have you followed the guidelines for contributing? - [ ] Have you signed the [CLA](http://www.ubuntu.com/legal/contributors/)? - [ ] Have you successfully run `make lint && make test`? - [ ] Have you added an entry to the changelog (`docs/reference/changelog.rst`)? --- The `ubuntu-26.04` backend cannot parse into a LXD backend because `ubuntu:26.04` doesn't yet exist - users instead must use `ubuntu-daily:26.04` for such images. This PR adds a temporary workaround to get us able to test on 26.04, but a larger task will be necessary for arriving at a long-term solution.