if fails during 

add_step

 stage for the very first step, because 

task_overrides

 contains invalid keys

I see, yes I guess it it makes sense to mark the pipeline as Failed 🙂
Could you add a GitHub issue on this behavior, so we do not miss it ?

the pipeline

How do I reproduce it? When I use add_step with the wrong parameter it throws an exception before the pipeline even starts ...

but at that point it hadn't actually added any steps. Maybe failed pipelines with zero steps count as completed

if fails during add_step stage for the very first step, because task_overrides contains invalid keys

it fails but with COMPLETED status

Which Task is marked "completed" the pipeline Task or the Step ?

Maybe failed pipelines with zero steps count as completed

zero steps counts as successful.
That said, how could it have zero steps if one of the steps failed? no?

For example, export_data returns task configuration that contains many keys that can be modified with task_overrides

But in the same time, it contains some keys that cannot be modified with task_overrides , for example project_name

You should add the wrong key to task_overrides , not the wrong parameter to add_step

try add_step(..., task_overrides={'project_name': 'my-awesome-project', ...})

Issue Verified, thanks!