ModuleNotFoundError in Lambda after Redeployment without Configuration Changes

Description

I am experiencing a ModuleNotFoundError when executing an AWS Lambda function. The error implies that the Lambda runtime cannot locate or recognize the handler module as a Python package. Notably, this issue appeared after redeploying the function without any modifications to the previously working path or configuration.

Error Details

• Timestamp: 2024-05-13T12:24:28.530Z
• File: /opt/.../exec_wrapper.py
• Error Message:

  [ERROR] Runtime.ImportModuleError: Unable to import module 'app/agents/mainAgent/lambda_function.handler': No module named 'app.agents'; 'app' is not a package
  Traceback (most recent call last):
  ...
  ModuleNotFoundError: No module named 'app.agents'; 'app' is not a package
  

Serverless.yml

mainAgent:
    description: Handle various type of text requests
    role: platformMainAgentRole
    handler: app/agents/mainAgent/lambda_function.handler
    architecture: arm64
    timeout: 60
    runtime: python3.9
  events:
      - schedule:
          rate: ${self:custom.rates.${self:provider.stage}}
          enabled: true
          inputTransformer:
            inputTemplate: '{}'
    layers:
      - { Ref: OpenaiLambdaLayer }
      - { Ref: TiktokenLambdaLayer }

Expected Behavior

The function should be able to find and import the handler module as it did before the redeployment, without any issues.

Actual Behavior

The function fails to start, throwing an error that it cannot find the specified module. This is puzzling as there were no changes in the Lambda's configuration or handler path that had previously been functional.

Steps to Reproduce

1. Setup the Lambda function with the handler path specified as app/agents/mainAgent/lambda_function.handler.
2. Deploy the function using the typical deployment process.
3. Attempt to invoke the function, triggering the error.

Additional Information

The sudden appearance of this issue in a stable setup raises concerns about potential changes or inconsistencies in the Lambda environment or deployment processes. Any insights or similar experiences shared by the community could help in pinpointing and resolving this issue.