trajectory need to be deepcopy!

[indeedzcr]

the difference reference and copy is as below:

a2={"aaa":1};b2={"bbb":2}
a1={"a2":a2};b1={"b2":b2}
ab={"a":a1,"b":b1}
dd=[]
dd.append(ab)
print(dd) # output is [{'a': {'a2': {'aaa': 1}}, 'b': {'b2': {'bbb': 2}}}]
a2["aaa"]=99;b2["bbb"]=99
print(dd) # output is [{'a': {'a2': {'aaa': 99}}, 'b': {'b2': {'bbb': 99}}}]

the dictionary in trajectory[2n]['info']['observation_metadata'] where n is 0,1,2,... , is actually a reference of ImageObservationProcessor.meta_data or TextObervationProcessor.meta_data.
The meta_data was created as the processor initialized, and then keep referenced all the time.
When processor.prosscess method runs and change the content of the meta_data, the trajectory changes then!
Thus: the 366 line of run_demo.py calls env.step then call _get_obs_metadata then call ObservationHandler.get_observation_metadata, it will finally reach the processor.meta_data modified by the processor.prosscess. After processor.prosscess modified the processor.meta_data, the trajectory was change the same time unexpectledy!
obs, _, terminated, _, info = env.step(action) # the 366 line of run_demo.py change the trajectory unexpectledy

Solution: use deepcopy the warp the obs and info

1. line 322 of run_demo.py
   state_info: StateInfo = {"observation": obs, "info": info}
   change to
   state_info: StateInfo = {"observation": deepcopy(obs), "info": deepcopy(info)}
2. line 367 of run_demo.py
   state_info = {"observation": obs, "info": info}
   change to
   state_info = {"observation": deepcopy(obs), "info": deepcopy(info)}