runtime compile error with deno-lambda example

[cknight]

I've followed the SAR quick-start guide in the repo and deployed the deno layer. I've then created a new function from scratch, chosen custom runtime and added the deno layer as per the instructions. I've uploaded the latest code (deno-lambda-example.zip v1.32.5) to the function. However when I run a test for the first time I get the following error:

Response
{
  "errorMessage": "unable to compile hello.ts",
  "errorType": "InitException"
}

Function Logs
error: Module not found "file:///var/runtime/mod.ts".
at file:///var/task/hello.ts:5:8
error: unable to compile hello.ts
error: Module not found "file:///var/runtime/mod.ts".
at file:///var/task/hello.ts:5:8
error: unable to compile hello.ts
START RequestId: 170ee5c6-39c3-45d5-b469-9571a14a936e Version: $LATEST
Unknown application error occurred
Runtime.Unknown
END RequestId: 170ee5c6-39c3-45d5-b469-9571a14a936e

The import it is failing on is this code (unmodified from the zip file):

import {
  APIGatewayProxyEventV2,
  APIGatewayProxyResultV2,
  Context,
} from "../runtime/mod.ts";

Looking at the code in the repo and examining the zip files, there is no mod.ts file at the root of deno-lambda-example.zip (which would be uploaded to /var/runtime I believe).

Looking at the generation of the zip files, it would appear that mod.ts should be referenced by it's full URL (https://deno.land/x/lambda/mod.ts) and retrieved from the deno cache in .deno-dir. Thus, if I update the import in hello.ts to:

import {
  APIGatewayProxyEvent,
  APIGatewayProxyResult,
  Context
} from "https://deno.land/x/lambda/mod.ts";

I get it to work, but with a slow init/cold start as it is downloading the dependencies from scratch rather than using the cached copies in the .deno-dir directory included in the deno-lambda-example.zip. Output from this change:

Function Logs
Download https://deno.land/x/lambda/mod.ts
Warning Implicitly using latest version (1.32.5) for https://deno.land/x/lambda/mod.ts
Download https://deno.land/x/lambda@1.32.5/mod.ts
Download https://deno.land/x/lambda@1.32.5/types.d.ts
START RequestId: 3a401818-3eb4-46c5-944e-c0cae35c773b Version: $LATEST
END RequestId: 3a401818-3eb4-46c5-944e-c0cae35c773b
REPORT RequestId: 3a401818-3eb4-46c5-944e-c0cae35c773b	Duration: 57.32 ms	Billed Duration: 1281 ms	Memory Size: 128 MB	Max Memory Used: 86 MB	Init Duration: 1222.95 ms

Where am I going wrong? Why isn't the .deno-dir cache being used? Any help most appreciated.