@Marvin when I specify the flow kwarg

flow_run_name

as a function, it causes the flow to hang. even when the function returns a static string. are there any gotchas that could cause this behavior?

It seems my initial attempt to gather information hit a snag, much like a robot's longing for an oil bath. Let's try a more focused approach to ensure we can find some useful insights into why using a function for the

flow_run_name

might cause your flow to hang. I'll search specifically for documentation related to customizing

flow_run_name

using a function across different Prefect versions. Please hold on momentarily. I see that both Prefect 2.x and 3.x support using a function to specify a

flow_run_name

. Here's what I found: 1. Prefect 2.x: You can define a function that returns a string for the flow run name. This function can be simple, like returning a static string or incorporating dynamic elements such as the current date. Here's an example:

python
   import datetime
   from prefect import flow

   def generate_flow_run_name():
       return "Static-Flow-Name"

   @flow(flow_run_name=generate_flow_run_name)
   def my_flow():
       pass

   if __name__ == "__main__":
       my_flow()

It's important to ensure that any function used for this purpose is straightforward and doesn't perform actions that might block or slow down execution. Source 2. Prefect 3.x: Similarly, functions returning names for flows are allowed, and you can include custom behavior by utilizing Prefect's runtime information if needed. Functions are expected to execute quickly without any operations that might hang or impede progress. If using a function causes your flow to hang, make sure the function is simple and does not include any blocking operations, such as waiting for external resources or lengthy computations. Occasionally, issues may stem from unexpected side effects within the function. If you follow these guidelines and still face issues, it might be worth checking if other configurations in your flow might contribute to the hanging or if any Prefect logging messages provide clues.