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<@ULVA73B9P> I have a deployed flow that I am tryi...
# ask-marvin
b
@Marvin I have a deployed flow that I am trying to run. When I pass it the expected parameters, it is exiting with this error: 
prefect.exceptions.SignatureMismatchError: Function expects parameters ['args', 'kwargs'] but was provided with parameters ['venue_id']
What might be going on here?
m
The error 
prefect.exceptions.SignatureMismatchError
occurs when the parameters provided to the flow do not match what the flow function expects. Here are some points to consider that could be causing this issue: 1. Parameter Names: Ensure that the parameters you are passing (
'venue_id'
) match exactly with the parameter names expected by the flow defined in the deployment script or YAML. 2. Deployment Configuration: In the deployment configuration, especially in 
deployment.yaml
, the parameters must match what is defined in the flow function. For example:
Copy code
parameters:
      venue_id: 1234
3. Using Keyword Arguments: You may pass **kwargs as parameters, this handles flexible argument passing. An example from the documentation states:
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parameters: {"name": "Marvin", "kwargs":{"cattype":"tabby","num": 42}}
4. Misleading Validation Errors: There are known issues where Prefect's parameter validation might show misleading errors due to how parameters are being passed within wrapped functions or decorators. Ensure that the parameters are managed properly to avoid 
kwargs
being interpreted as 
args
. Example:
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def my_flow(*args, **kwargs): # Ensure kwargs are in place to handle any mismatch issues.
        venue_id = kwargs.get('venue_id')
### Related GitHub Issues - Misleading parameter validation error - Argument &amp; Keyword Argument Binding Issues These issues could provide more context or indicate there might be a Prefect bug affecting your scenario. ### Steps to resolve: 1. Inspect your flow's function signature to confirm the parameters it expects. 2. Verify your 
deployment.yaml
for correct parameter configuration. 3. Modify your flow function to accept 
**kwargs
if necessary. 4. Check out the linked GitHub issues for any workarounds or fixes. You can find more details on these topics in the Prefect documentation.
It seems the 
SignatureMismatchError
you're encountering is related to known issues with how Prefect handles parameter passing, particularly when dealing with functions that use 
args
and 
kwargs
. Here are some relevant issues from GitHub that align with your problem: 1. Prefect Task arg/kwarg binding issue: - Arg/kwarg binding can confuse args with kwargs, especially in decorated functions. - Example: If a function uses 
@wraps
, it might misinterpret which parameters are args and which are kwargs. - Issue Link: https://github.com/PrefectHQ/prefect/issues/8753 2. Misleading parameter validation error: - Parameter validation might incorrectly identify parameters as 
args
and 
kwargs
even if they're explicitly specified. - Ensure that the parameters passed in 
deployment.yaml
match those expected by the flow. - Issue Link: https://github.com/PrefectHQ/prefect/issues/14663 3. Handling kwargs in deployments: - If using 
**kwargs
in your flow function, ensure that the deployment parameters account for this. - Example workaround involves wrapping 
kwargs
in another dictionary. - Issue Link: https://github.com/PrefectHQ/prefect/issues/6039 ### Recommendations: 1. Check Deployment Configuration: Ensure that your 
deployment.yaml
accurately reflects the parameters expected by your flow.
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yaml
    parameters:
      venue_id: 1234
2. Use Explicit Parameter Handling: If using 
kwargs
, structure them clearly.
Copy code
python
    @flow
    def your_flow_function(venue_id=None, **kwargs):
        # Your code here
For more detailed debugging or context, refer to the issue links provided. They contain a wealth of information and potential workarounds that may apply to your case.
n
yeah this first github issue is related to your ask
gosh, whoops i mean this one
b
oh nice
thanks cap
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