config.list websocket call results in: '<' not supported between instances of 'NoneType' and 'str'

[Björn Tillenius]

Loading the machine details page currently fails for this deployment:

  http://10.245.136.7:5240/MAAS/l/machine/ytyknh

It's running 2.9.0~beta8-9090-g.f7352c333 from the snap.

Looking at the debug console, I see that the config.list websocket call returned this error:

  error: "'<' not supported between instances of 'NoneType' and 'str'"

[Adam Collard (adam-collard)]

https://paste.ubuntu.com/p/PgctrNDwpD/ is the traceback from the logs

[Xav Paice (xavpaice)]

Using Maas 2.6.2-7841-ga10625be3-0ubuntu1~18.04.1 from http://ppa.launchpad.net/maas/stable/ubuntu bionic/main, I got the same error when I added the 'focal' image where previously it was just '18.04' and '16.04'. Currently the Maas GUI is unusable as every page returns '<' not supported between instances of 'NoneType' and 'str'.

I don't see a way using the CLI to delete the 'focal' image, which leaves me unable to use Maas via GUI any longer. Any suggestions for a workaround other than upgrading (which is a much larger task)?