Do ops allow dynamic input types? When I try to define an input as a Union of 2 types, I get "DagsterInvalidDefinitionError: Problem using type 'typing.Union[typing.List[typing.Dict], pandas.core.frame.DataFrame]' from type annotation for argument 'examples', correct the issue or explicitly set the dagster_type via In()"

hey @Eric Loreaux can you share a code sample?

Hi Jamie, I redesigned the pipeline to move away from relying on a Union of types, which resolved the issue. Based on your response, I'm assuming that dagster should support unions as op arg types or return types?

You might need to define a custom dagster type, but it’s hard to know if you need to do that or if there’s another syntax issue without looking at the code

Got it, thanks. It does seem like the error message I encountered could be made to be slightly more informative. I will revive this thread if I encounter the issue again