I have some issue with the libiconv "translit" option using the library in a alpine 3.20 image

here the go code to reproduce :

main.go

package main

import (
    "fmt"

    iconv "github/djimenez/iconv-go"
)

func main() {
    output := make([]byte, 20)
    nRead, nWrite, err := iconv.Convert([]byte("éé"), output, "UTF-8", "ASCII//TRANSLIT")
    fmt.Println(nRead, nWrite, err)

}

go.mod

module truc

go 1.22.4

require github/djimenez/iconv-go v0.0.0-20160305225143-8960e66bd3da // indirect

Dockerfile

FROM golang:1.22-alpine3.20 as builder
RUN apk --no-cache add build-base gnu-libiconv-libs
WORKDIR /src
#copy go mod and run go get to hit cache if no new deps
COPY ./go.* ./
RUN  go mod download
COPY . .
RUN  go build  -o "test-iconv" .



FROM alpine:3.20  as runtime
RUN apk --no-cache add gnu-libiconv-libs
COPY --from=builder /src/test-iconv /app/
RUN adduser connector --disabled-password && chown connector. -R /app && chmod 700 "/app/test-iconv"
USER connector  
#entrypoint
ENTRYPOINT ["/app/test-iconv"] 

then launch :

docker build . -t test-iconv && docker run test-iconv

I want the output 4 2 nil, but i got :

0 0 invalid argument

if i switch the builder and runtime image to ubuntu based golang:1.22, the problem disapear, but the image is now much bigger (800MB instead of 18MB)...

What am i missing in alpine way ?

Thank you.