Context deadline exceeded at start locally

I'm running the lambda image locally, and long story short, it starts off with an expired context deadline.

```golang
package main

import (
"context"
"log"

"github.com/aws/aws-lambda-go/lambda"
)

func Handler(ctx context.Context) {
log.Println(ctx.Err())
log.Println(ctx.Deadline())
}
func main() {
lambda.Start(Handler)
}
```

```dockerfile
# installer
FROM golang:1.15-alpine3.12@sha256:4d8abd16b03209b30b48f69a2e10347aacf7ce65d8f9f685e8c3e20a512234d9 as installer
WORKDIR /build

COPY ./go.mod ./go.sum ./

RUN go mod download

# builder
FROM installer as builder

COPY . ./

RUN CGO_ENABLED=0 GOOS=linux go build -o Main ./main.go

# release
FROM public.ecr.aws/lambda/go:latest

COPY --from=builder /build/Main .

CMD ["./Main"]
```

`curl localhost:8080/2015-03-31/functions/function/invocations`

logs

```
time="2021-02-27T23:20:12.39" level=info msg="exec '/var/runtime/bootstrap' (cwd=/var/task, handler=)"
time="2021-02-27T23:20:48.623" level=info msg="extensionsDisabledByLayer(/opt/disable-extensions-jwigqn8j) -> stat /opt/disable-extensions-jwigqn8j: no such file or directory"
time="2021-02-27T23:20:48.624" level=warning msg="Cannot list external agents" error="open /opt/extensions: no such file or directory"
START RequestId: 9af7aefe-d612-4f5e-9e75-c9cdeadab9f5 Version: $LATEST
2021/02/27 23:20:48 context deadline exceeded
2021/02/27 23:20:48 2021-02-27 23:20:48.631152628 +0000 UTC true
END RequestId: 9af7aefe-d612-4f5e-9e75-c9cdeadab9f5
REPORT RequestId: 9af7aefe-d612-4f5e-9e75-c9cdeadab9f5 Init Duration: 0.20 ms Duration: 7.73 ms Billed Duration: 100 ms Memory Size: 3008 MB Max Memory Used: 3008 MB
```

"context deadline exceeded"

What am I missing? [Here](https://docs.aws.amazon.com/lambda/latest/dg/golang-context.html) it says

> Context methods
Deadline – Returns the date that the execution times out, in Unix time milliseconds.

But it's essentially returning the starting time instead.