@Marvin what causes this

Flow could not be retrieved from deployment.
Traceback (most recent call last):
  File "/usr/local/lib/python3.9/site-packages/prefect/engine.py", line 246, in retrieve_flow_then_begin_flow_run
    flow = await load_flow_from_flow_run(flow_run, client=client)
  File "/usr/local/lib/python3.9/site-packages/prefect/client.py", line 105, in with_injected_client
    return await fn(*args, **kwargs)
  File "/usr/local/lib/python3.9/site-packages/prefect/deployments.py", line 50, in load_flow_from_flow_run
    basepath = deployment.path or Path(deployment.manifest_path).parent
  File "/usr/local/lib/python3.9/pathlib.py", line 1082, in __new__
    self = cls._from_parts(args, init=False)
  File "/usr/local/lib/python3.9/pathlib.py", line 707, in _from_parts
    drv, root, parts = self._parse_args(args)
  File "/usr/local/lib/python3.9/pathlib.py", line 691, in _parse_args
    a = os.fspath(a)
TypeError: expected str, bytes or os.PathLike object, not NoneType

It looks like you're encountering a

TypeError

when the program expects a string, bytes, or os.PathLike object but receives a

NoneType

object instead. This issue occurs in the context of retrieving a flow from a deployment in Prefect. The problem originates from this line in the stack trace:

python
basepath = deployment.path or Path(deployment.manifest_path).parent

Here's a breakdown of the possible causes: 1. Missing Deployment Details: The

deployment.path

or

deployment.manifest_path

attributes could be

None

. This scenario is likely if the deployment wasn't set up correctly or if there's a mismatch in your deployment configuration. 2. Configuration Issue: There might be a configuration problem or missing data in the database or YAML file defining your deployment. 3. Prefect Version: This error might also vary based on the version of Prefect you're using. Prefect 2.x and 3.x might have differences in handling flow retrieval. To resolve this issue, ensure that the deployment is correctly configured. Verify that the

deployment.path

and/or

deployment.manifest_path

are properly set and not

None

for the flow you're trying to run. Let's quickly check the Prefect documentation for more precise solutions based on the Prefect version you might be using. Could you confirm which version of Prefect you're working with?

The path should be a s3 bucket

The error you're encountering indicates a problem with loading a deployment path, specifically when using S3 storage with Prefect version 3.x. Here's a summary of possible solutions based on the documentation: 1. Ensure Correct S3 Configuration: - Make sure your S3 path is correctly specified in the deployment configuration. The

bucket

and

folder

need to be accurately defined. - Double-check that your Prefect deployment YAML or CLI options properly reference the S3 bucket and path, as shown in the Prefect 3.x documentation examples. 2. Use Prefect-AWS Plugin: - If your bucket is private, ensure that you've installed the Prefect-AWS plugin (

prefect-aws

) and have properly configured AWS credentials blocks. - Use the

push_to_s3

step from the

prefect_aws.deployments

in your deployment configuration to manage code upload to S3. 3. Correct Use of CLI: - When using the Prefect CLI for deployment, check that all paths are set explicitly and ensure no part of the path (like

manifest_path

) is left undefined. 4. Infrastructure and Storage Blocks: - Using infrastructure and storage blocks may help clarify and isolate path configuration issues. Prefect allows using blocks for specifying storage and pulling code from a specific location. Here are relevant sections of the Prefect 3.x documentation: - Using S3 for storage and deployment: Prefect Deploy with AWS S3 - Using infrastructure blocks: Prefect Infrastructure Concepts By revisiting your deployment configuration, ensuring all paths are explicitly set, and using the AWS plugin for credentials, you should be able to resolve the

NoneType

error.