Comment 6 for bug 2012306

Only seems to be these two units, I'm not sure how to retry with a 2.8 cli when other units in this model are already upgraded and on 2.9.42.

Here's `juju status --format=yaml` output:

| https://pastebin.canonical.com/p/VSzd7B7yCY/

What's odd is that the other unit having this issue, container-log-archive-launchpad-frontend/, juju status reports 2.9.42 when it is not:

          container-log-archive-launchpad-frontend/6:
            workload-status:
              current: active
              message: Ready (source version/commit bdb3f4a)
              since: 22 Sep 2022 14:05:43Z
            juju-status:
              current: idle
              since: 20 Mar 2023 18:25:30Z
              version: 2.9.42
            leader: true
            public-address: 10.131.66.248

ubuntu@juju-4112d9-prod-launchpad-manual-servers-0:~$ tail -f /var/log/juju/unit-container-log-archive-launchpad-frontend-6.log -n 5
2023-03-21 04:30:13 ERROR juju.worker.upgrader upgrader.go:250 failed to fetch agent binaries from "": Get "": unsupported protocol scheme ""
2023-03-21 04:30:18 INFO juju.worker.upgrader upgrader.go:191 desired agent binary version: 2.9.42
2023-03-21 04:30:18 INFO juju.worker.upgrader upgrader.go:220 upgrade requested from 2.8.9 to 2.9.42
2023-03-21 04:30:18 INFO juju.worker.upgrader upgrader.go:280 fetching agent binaries from ""
2023-03-21 04:30:18 ERROR juju.worker.upgrader upgrader.go:250 failed to fetch agent binaries from "": Get "": unsupported protocol scheme ""
2023-03-21 04:30:23 INFO juju.worker.upgrader upgrader.go:191 desired agent binary version: 2.9.42
2023-03-21 04:30:23 INFO juju.worker.upgrader upgrader.go:220 upgrade requested from 2.8.9 to 2.9.42
2023-03-21 04:30:23 INFO juju.worker.upgrader upgrader.go:280 fetching agent binaries from ""
2023-03-21 04:30:23 ERROR juju.worker.upgrader upgrader.go:250 failed to fetch agent binaries from "": Get "": unsupported protocol scheme ""
^C