I think it because of these None values:

'timesteps_total': None,
 'episodes_total': None,

ohh yeah, Flyte does not like Nones, we have been converting it to empty strings 😅 maybe nested None doesnt work, but it should support Optional or None starting from 1.1 i think

yes, could you try Dict[str, Optional[Any]]

@glamorous-carpet-83516, I tried and got:

File "/Users/fshen/hbo-code/dai-mle-models/env/lib/python3.8/site-packages/flytekit/core/type_engine.py", line 1060, in to_literal
    raise TypeError("Ambiguous choice of variant for union type")

this is also a bit like a grab bag of entries. would it be possible for you to convert it into a dataclass?

an untyped

dict

should do the trick here too

@rich-garden-69988, how do you define a untyped dict in a return type? Like this?

-> typing.Dict

yes

@rich-garden-69988, it works! Thank you very much!

yup got it.

of course, the DictTransformer is very versatile - I ran into the same issue before, but found this fix!