sam warnings for non existent layer

Question

sam build is spitting out weird warnings

```
WARNING: No BuildArchitecture specifed in Layer `None` Metadata. Defaulting to x86_64.
```
This is happening only for sam versions 1.104 and above. I have no idea what this is referring to since it is specifying layer 'None' even when there is no layer in the application. My code still seems to work but this is concerning. Can't specify metadata for something that doesn't exist.

Answer

This is a bug: https://github.com/aws/aws-sam-cli/issues/6444

Answer

This warning is indicating that the SAM build process is unable to determine the architecture (x86_64) for one of the layers in your SAM application.

This can happen for a few reasons:

There may be a layer defined in your template that does not have the "Architecture" property specified. The SAM build needs this to know which architecture to use.

There could be a bug in newer versions of the SAM CLI where it is incorrectly reporting this warning even when all layers are properly defined.
As Yusuf pointed out, this is the case: https://github.com/aws/aws-sam-cli/issues/6444

sam warnings for non existent layer

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