cockpit image builder interface for osbuild-composesr works fine.
However, when I try the CLI it fails:
$ sudo composer-cli blueprints push vim_bash_machine.toml
ERROR: BlueprintsError: 400 Bad Request: The browser (or proxy) sent a request that this server could not understand: Near line 19 (last key parsed ''): Key '' was already created and cannot be used as an array.
Fedora 34 fully updated.