user_and_multistage

user@whale:~/minim$ cat Dockerfile 
FROM ocaml/opam:alpine-3.5_ocaml-4.04.0 as ocaml

FROM scratch

COPY --from=ocaml /bin/sh /
CMD ["/sh"]
user@whale:~/minim$ docker build -t minim .
Sending build context to Docker daemon  53.76kB
Step 1/4 : FROM ocaml/opam:alpine-3.5_ocaml-4.04.0 as ocaml
 ---> 71e233abdbbf
Step 2/4 : FROM scratch
 ---> 
Step 3/4 : COPY --from=ocaml /bin/sh /
 ---> Using cache
 ---> 9fe76f919a20
Step 4/4 : CMD /sh
 ---> Using cache
 ---> f01e19719430
Successfully built f01e19719430
Successfully tagged minim:latest
user@whale:~/minim$ docker run -it minim:latest
docker: Error response from daemon: linux spec user: unable to find user opam: no matching entries in passwd file.