How to configure environments using hydra?

[Divelix]

My goal is to make both agent and environment parameters saved in logs of experiment. I managed to instantiate everything related to agents in hydra, but environment seems harder: e.g. if I try to define observations something like this

_target_: source.standalone.tutorials.03_envs.create_quadruped_base_env.ObservationsCfg

and call by

import hydra
observations = hydra.utils.instantiate(cfg.observations)

it will throw

Error executing job with overrides: []
Error locating target 'source.standalone.tutorials.03_envs.create_quadruped_base_env.ObservationsCfg'

My guess is that @configclass somehow breaks env classes.
Does anyone know how to fix this error or any better way to configure envs using hydra?