Comment 3 for bug 1898040

Where are you pulling that interface layer from? The repo that the layer-index entry [1] refers to doesn't have that file [2].

It sounds like you're using a version that someone tried to convert to work with both frameworks; if that's the case, you either need to add the Operator Framework files to the exclude list in the interface.yaml [3] or convert it to use the ops-reactive-interface library [4] which allows you to focus on the Operator Framework implementation only and then make it usable in Reactive Framework charms. The main downside of the latter approach is that it does require changing how the interface is included into the charm (it's a library, so it's pulled in via wheelhouse.txt rather than layer.yaml) but it ends up with a much cleaner implementation and encourages moving fully to the new framework. But, the former does allow you to fix this bug with a simple two-line addition to a YAML file, so there's that.

[1]: https://github.com/juju/layer-index/blob/master/interfaces/prometheus.json#L4
[2]: https://git.launchpad.net/interface-prometheus/tree/
[3]: https://charm-tools.readthedocs.io/en/latest/tactics.html#charmtools.build.tactics.ExcludeTactic
[4]: https://github.com/juju-solutions/ops-reactive-interface