exec /main: no such file or directory when building docker image of Go app

I have a golang application which I want to dockerize and run on AWS Lambda. Here is my Dockerfile:

FROM golang:1.21 as buildWORKDIR /appRUN apt-get updateRUN apt-get install -y libvips libvips-devCOPY go.mod go.sum ./COPY main.go .RUN GOOS=linux GOARCH=amd64 go build -o main main.goFROM alpine:3.19COPY --from=build /app/main /mainENTRYPOINT [ "/main" ]

I install libvips because I am using bimg library for image compression.

Here is my minified go app:

package mainimport ("context""log""github.com/aws/aws-lambda-go/events""github.com/aws/aws-lambda-go/lambda""github.com/aws/aws-sdk-go-v2/config""github.com/aws/aws-sdk-go-v2/service/s3""github.com/h2non/bimg")var (    s3Client *s3.Client)func init() {    cfg, err := config.LoadDefaultConfig(context.Background())    if err != nil {        log.Fatalf("failed to load AWS config: %v", err)    }    s3Client = s3.NewFromConfig(cfg)}func main() {    lambda.Start(Handler)}func Handler(ctx context.Context, event events.S3Event) error {    // compress and upload and do stuff    return nil}

Not only I get the error exec /main: no such file or directory when I try to test the lambda from aws dashboard, but it also gives me the same error when I try to run the image on my local machine with the following command:

docker run --rm -it  s3-image-compressor-lambda:latest

I know the lambda won't work on my local machine but I believe it shouldn't say file not found but rather I would expect a runtime error.

UPDATE: I added some commands to Dockerfile to try to debug to see what's going on.

I added RUN ls -l / right after COPY of the main file and here is the output:

#16 [stage-1 4/7] RUN ls -l /#16 0.354 total 18668#16 0.354 drwxr-xr-x    2 root     root          4096 Jan 26 17:53 bin#16 0.354 drwxr-xr-x    5 root     root           340 Apr  4 22:28 dev#16 0.354 drwxr-xr-x    1 root     root          4096 Apr  4 22:28 etc#16 0.354 drwxr-xr-x    2 root     root          4096 Jan 26 17:53 home#16 0.354 drwxr-xr-x    7 root     root          4096 Jan 26 17:53 lib#16 0.354 -rwxr-xr-x    1 root     root      19055376 Apr  4 22:06 main#16 0.354 drwxr-xr-x    5 root     root          4096 Jan 26 17:53 media#16 0.354 drwxr-xr-x    2 root     root          4096 Jan 26 17:53 mnt#16 0.354 drwxr-xr-x    2 root     root          4096 Jan 26 17:53 opt#16 0.354 dr-xr-xr-x  459 root     root             0 Apr  4 22:28 proc#16 0.354 drwx------    2 root     root          4096 Jan 26 17:53 root#16 0.354 drwxr-xr-x    2 root     root          4096 Jan 26 17:53 run#16 0.354 drwxr-xr-x    2 root     root          4096 Jan 26 17:53 sbin#16 0.354 drwxr-xr-x    2 root     root          4096 Jan 26 17:53 srv#16 0.354 dr-xr-xr-x   13 root     root             0 Apr  4 22:28 sys#16 0.354 drwxrwxrwt    2 root     root          4096 Jan 26 17:53 tmp#16 0.354 drwxr-xr-x    7 root     root          4096 Jan 26 17:53 usr#16 0.354 drwxr-xr-x   12 root     root          4096 Jan 26 17:53 var#16 DONE 0.4s

So there is actually a main file in the root directory.

After that I added RUN /main to see what is gonna happen, and here is the output:

> [stage-1 8/8] RUN /main:0.258 /bin/sh: /main: not found