fix: add warning message for job-prefixed pipeline steps when no job …

…name is provided

src/sagemaker/workflow/utilities.py

@@ -41,6 +41,14 @@
     "if desired."
 )
 
+# pylint: disable=C0301
+JOB_KEY_NONE_WARN_MSG_TEMPLATE = (
+    "Invalid input: the use_custom_job_prefix is set but the name field [{}] has not been specified. "
+    "Please refer to the AWS Docs to identify which field should be set to enable the "
+    "custom-prefixing feature for jobs created via a pipeline execution. "
+    "https://docs.aws.amazon.com/sagemaker/latest/dg/build-and-manage-access.html#build-and-manage-step-permissions-prefix"
+)
+
 if TYPE_CHECKING:
     from sagemaker.workflow.step_collections import StepCollection
 
@@ -458,6 +466,8 @@ def trim_request_dict(request_dict, job_key, config):
         request_dict.pop(job_key, None)  # safely return null in case of KeyError
     else:
         if job_key in request_dict:
+            if request_dict[job_key] is None:
+                raise ValueError(JOB_KEY_NONE_WARN_MSG_TEMPLATE.format(job_key))
             request_dict[job_key] = base_from_name(request_dict[job_key])  # trim timestamp
 
     return request_dict