Dockerfile

FROM alpine
RUN apk add --no-cache gcc musl-dev
ADD env.c /env.c
RUN gcc -static -o /env /env.c -Wno-implicit-function-declaration

FROM scratch
COPY --from=0 /env /env
ENTRYPOINT ["/env"]

env.c

int main(int argc, char **argv, char** envp) { for(char** env=envp;*env!=0;env++) puts(*env, "\n"); }

out

$ docker build --compress --squash --force-rm --tag "${PWD##*/}" .
Sending build context to Docker daemon     357B
Step 1/7 : FROM alpine
latest: Pulling from library/alpine
8e3ba11ec2a2: Already exists 
Digest: sha256:7043076348bf5040220df6ad703798fd8593a0918d06d3ce30c6c93be117e430
Status: Downloaded newer image for alpine:latest
 ---> 11cd0b38bc3c
Step 2/7 : RUN apk add --no-cache gcc musl-dev
 ---> Running in 3d3e7bf3fcdd
fetch http://dl-cdn.alpinelinux.org/alpine/v3.8/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.8/community/x86_64/APKINDEX.tar.gz
(1/12) Installing binutils (2.30-r5)
(2/12) Installing gmp (6.1.2-r1)
(3/12) Installing isl (0.18-r0)
(4/12) Installing libgomp (6.4.0-r8)
(5/12) Installing libatomic (6.4.0-r8)
(6/12) Installing pkgconf (1.5.3-r0)
(7/12) Installing libgcc (6.4.0-r8)
(8/12) Installing mpfr3 (3.1.5-r1)
(9/12) Installing mpc1 (1.0.3-r1)
(10/12) Installing libstdc++ (6.4.0-r8)
(11/12) Installing gcc (6.4.0-r8)
(12/12) Installing musl-dev (1.1.19-r10)
Executing busybox-1.28.4-r0.trigger
OK: 99 MiB in 25 packages
Removing intermediate container 3d3e7bf3fcdd
 ---> c91ce4d7d290
Step 3/7 : ADD env.c /env.c
 ---> b8d74fb55c38
Step 4/7 : RUN gcc -static -o /env /env.c -Wno-implicit-function-declaration
 ---> Running in 5d65a7634564
Removing intermediate container 5d65a7634564
 ---> 67ef1cb241da
Step 5/7 : FROM scratch
 ---> 
Step 6/7 : COPY --from=0 /env /env
 ---> d8ebacb21942
Step 7/7 : ENTRYPOINT ["/env"]
 ---> Running in c7844c2514c8
Removing intermediate container c7844c2514c8
 ---> 727b7bbfd0ac
Successfully built 390f409f8c32
Successfully tagged tmm:latest

$ docker run --rm "${PWD##*/}" -e IMSET=1
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
HOSTNAME=b65d45c6440c
HOME=/