Bug: pydantic platform incompatibility when using layer for arm64 lambda

[nosta33]

Expected Behaviour

When developing an AWS lambda configured with arm64 architecture, and using AWS Powertools implemented with layer arn:aws:lambda:eu-west-1:017000801446:layer:AWSLambdaPowertoolsPythonV3-python313-arm64:7, all packages and dependencies are correctly installed with the right platform configuration.

Current Behaviour

When developing an AWS lambda configured with arm64 architecture, and using AWS Powertools implemented with layer arn:aws:lambda:eu-west-1:017000801446:layer:AWSLambdaPowertoolsPythonV3-python313-arm64:7, my lambda immediately crashes raising the error : no module named 'pydantic_core._pydantic_core'.

Code snippet

Run a lambda with arm64 architecture and layer arn:aws:lambda:eu-west-1:017000801446:layer:AWSLambdaPowertoolsPythonV3-python313-arm64:7

Possible Solution

When looking at the pydantic package, I see :

which shows that the architecture is x86 and not arm64.

Steps to Reproduce

Run a lambda with arm64 architecture and layer arn:aws:lambda:eu-west-1:017000801446:layer:AWSLambdaPowertoolsPythonV3-python313-arm64:7

Powertools for AWS Lambda (Python) version

latest

AWS Lambda function runtime

3.13

Packaging format used

Lambda Layers

Debugging logs

[boring-cyborg]

Thanks for opening your first issue here! We'll come back to you as soon as we can.
In the meantime, check out the #python channel on our Powertools for AWS Lambda Discord: Invite link

[leandrodamascena]

Hey @nosta33! Thanks for opening this bug and reporting a potential issue! I tried to reproduce this and I was not able.

I'm using the Layer arn:aws:lambda:eu-west-1:017000801446:layer:AWSLambdaPowertoolsPythonV3-python313-arm64:7.

I'm running this code:

import json
from pydantic.version import VERSION

def lambda_handler(event, context):
    print("Pydantic version ->", VERSION)
    # TODO implement
    return {
        'statusCode': 200,
        'body': json.dumps('Hello from Lambda!')
    }

And I have this output:

START RequestId: f7ac8911-92ab-4427-ab51-4e952171293a Version: $LATEST
Pydantic version -> 2.10.6
END RequestId: f7ac8911-92ab-4427-ab51-4e952171293a
REPORT RequestId: f7ac8911-92ab-4427-ab51-4e952171293a	Duration: 2.11 ms	Billed Duration: 3 ms	Memory Size: 128 MB	Max Memory Used: 41 MB	Init Duration: 150.10 ms	

I also downloaded this layer and I can see the correct _pydantic_core.cpython-313-aarch64-linux-gnu.so file there.

Can you tell me a little more about how to reproduce this error?

[nosta33]

Thank you for the blasing fast answer @leandrodamascena .
Actually, the issue comes from my script that overrode the pydantic version because of the use of pip cache.
Sorry about that!

Take care.

[github-actions]

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