make win doesn't work

[chardch]

Description

Unable to build dockerd.exe for windows using make win

Steps to reproduce the issue:

make win

Describe the results you received:

docker build  --build-arg=GO_VERSION  -f "Dockerfile" --target=final   -t "docker-dev:master" .
[+] Building 55.1s (66/66) FINISHED                                                                                                                                                                                 
 => [internal] load .dockerignore                                                                                                                                                                              0.0s
 => => transferring context: 87B                                                                                                                                                                               0.0s
 => [internal] load build definition from Dockerfile                                                                                                                                                           0.0s
 => => transferring dockerfile: 16.55kB                                                                                                                                                                        0.0s
 => resolve image config for docker.io/docker/dockerfile:1.1.7-experimental                                                                                                                                    0.0s
 => CACHED docker-image://docker.io/docker/dockerfile:1.1.7-experimental                                                                                                                                       0.0s
 => [internal] load metadata for docker.io/library/golang:1.13.15-buster                                                                                                                                       0.0s
 => [internal] load metadata for docker.io/library/debian:buster                                                                                                                                               0.2s
 => [internal] load metadata for docker.io/djs55/vpnkit:0.4.0                                                                                                                                                  0.0s
 => [internal] load build context                                                                                                                                                                              0.6s
 => => transferring context: 53.17MB                                                                                                                                                                           0.5s
 => CACHED [vpnkit 1/1] FROM docker.io/djs55/vpnkit:0.4.0                                                                                                                                                      0.0s
 => [base 1/3] FROM docker.io/library/golang:1.13.15-buster                                                                                                                                                    0.0s
 => [frozen-images 1/4] FROM docker.io/library/debian:buster@sha256:22d4552b9f96fd0ea943cb846d58b069d4df297673636055a3d984b3ccac6a28                                                                           0.0s
 => CACHED [frozen-images 2/4] RUN --mount=type=cache,sharing=locked,id=moby-frozen-images-aptlib,target=/var/lib/apt     --mount=type=cache,sharing=locked,id=moby-frozen-images-aptcache,target=/var/cache/  0.0s
 => CACHED [frozen-images 3/4] COPY contrib/download-frozen-image-v2.sh /                                                                                                                                      0.0s
 => [frozen-images 4/4] RUN /download-frozen-image-v2.sh /build         buildpack-deps:buster@sha256:d0abb4b1e5c664828b93e8b6ac84d10bce45ee469999bef88304be04a2709491         busybox:latest@sha256:95cf004f  21.4s
 => CACHED [base 2/3] RUN echo 'Binary::apt::APT::Keep-Downloaded-Packages "true";' > /etc/apt/apt.conf.d/keep-cache                                                                                           0.0s
 => CACHED [base 3/3] RUN sed -ri "s/(httpredir|deb).debian.org/${APT_MIRROR:-deb.debian.org}/g" /etc/apt/sources.list  && sed -ri "s/(security).debian.org/${APT_MIRROR:-security.debian.org}/g" /etc/apt/so  0.0s
 => CACHED [tini 1/2] RUN --mount=type=cache,sharing=locked,id=moby-tini-aptlib,target=/var/lib/apt     --mount=type=cache,sharing=locked,id=moby-tini-aptcache,target=/var/cache/apt         apt-get update   0.0s
 => [tini 2/2] RUN --mount=type=cache,target=/root/.cache/go-build     --mount=type=cache,target=/go/pkg/mod     --mount=type=bind,src=hack/dockerfile/install,target=/tmp/install         PREFIX=/build /tmp  4.4s
 => CACHED [runtime-dev-cross-false 1/1] RUN --mount=type=cache,sharing=locked,id=moby-cross-false-aptlib,target=/var/lib/apt     --mount=type=cache,sharing=locked,id=moby-cross-false-aptcache,target=/var/  0.0s
 => [runc 1/1] RUN --mount=type=cache,target=/root/.cache/go-build     --mount=type=cache,target=/go/pkg/mod     --mount=type=bind,src=hack/dockerfile/install,target=/tmp/install         PREFIX=/build /tm  12.9s
 => CACHED [containerd 1/2] RUN --mount=type=cache,sharing=locked,id=moby-containerd-aptlib,target=/var/lib/apt     --mount=type=cache,sharing=locked,id=moby-containerd-aptcache,target=/var/cache/apt        0.0s
 => [containerd 2/2] RUN --mount=type=cache,target=/root/.cache/go-build     --mount=type=cache,target=/go/pkg/mod     --mount=type=bind,src=hack/dockerfile/install,target=/tmp/install         PREFIX=/bui  49.5s
 => [rootlesskit 1/3] RUN --mount=type=cache,target=/root/.cache/go-build     --mount=type=cache,target=/go/pkg/mod     --mount=type=bind,src=hack/dockerfile/install,target=/tmp/install         PREFIX=/bu  11.7s
 => [vndr 1/1] RUN --mount=type=cache,target=/root/.cache/go-build     --mount=type=cache,target=/go/pkg/mod     --mount=type=bind,src=hack/dockerfile/install,target=/tmp/install         PREFIX=/build /tmp  5.4s
 => [gotestsum 1/1] RUN --mount=type=cache,target=/root/.cache/go-build     --mount=type=cache,target=/go/pkg/mod     --mount=type=bind,src=hack/dockerfile/install,target=/tmp/install         PREFIX=/buil  10.1s
 => [proxy 1/1] RUN --mount=type=cache,target=/root/.cache/go-build     --mount=type=cache,target=/go/pkg/mod     --mount=type=bind,src=hack/dockerfile/install,target=/tmp/install         PREFIX=/build /t  11.8s
 => [golangci_lint 1/1] RUN --mount=type=cache,target=/root/.cache/go-build     --mount=type=cache,target=/go/pkg/mod     --mount=type=bind,src=hack/dockerfile/install,target=/tmp/install         PREFIX=/  20.5s
 => [tomlv 1/1] RUN --mount=type=cache,target=/root/.cache/go-build     --mount=type=cache,target=/go/pkg/mod     --mount=type=bind,src=hack/dockerfile/install,target=/tmp/install         PREFIX=/build /tm  5.1s
 => [dockercli 1/1] RUN --mount=type=cache,target=/root/.cache/go-build     --mount=type=cache,target=/go/pkg/mod     --mount=type=bind,src=hack/dockerfile/install,target=/tmp/install         PREFIX=/build  3.0s
 => [shfmt 1/1] RUN --mount=type=cache,target=/root/.cache/go-build     --mount=type=cache,target=/go/pkg/mod     --mount=type=bind,src=hack/dockerfile/install,target=/tmp/install         PREFIX=/build /tm  8.8s
 => CACHED [registry 1/2] WORKDIR /go/src/github.com/docker/distribution                                                                                                                                       0.0s
 => CACHED [registry 2/2] RUN --mount=type=cache,target=/root/.cache/go-build     --mount=type=cache,target=/go/pkg/mod     --mount=type=tmpfs,target=/go/src/         set -x         && git clone https://gi  0.0s
 => CACHED [criu 1/2] RUN --mount=type=cache,sharing=locked,id=moby-criu-aptlib,target=/var/lib/apt     --mount=type=cache,sharing=locked,id=moby-criu-aptcache,target=/var/cache/apt         apt-get update   0.0s
 => CACHED [criu 2/2] RUN mkdir -p /usr/src/criu     && curl -sSL https://github.com/checkpoint-restore/criu/archive/v3.14.tar.gz | tar -C /usr/src/criu/ -xz --strip-components=1     && cd /usr/src/criu     0.0s
 => [rootlesskit 2/3] COPY ./contrib/dockerd-rootless.sh /build                                                                                                                                                0.1s
 => [rootlesskit 3/3] COPY ./contrib/dockerd-rootless-setuptool.sh /build                                                                                                                                      0.1s
 => CACHED [dev-systemd-false  1/26] RUN groupadd -r docker                                                                                                                                                    0.0s
 => CACHED [dev-systemd-false  2/26] RUN useradd --create-home --gid docker unprivilegeduser  && mkdir -p /home/unprivilegeduser/.local/share/docker  && chown -R unprivilegeduser /home/unprivilegeduser      0.0s
 => CACHED [dev-systemd-false  3/26] RUN ln -sfv /go/src/github.com/docker/docker/.bashrc ~/.bashrc                                                                                                            0.0s
 => CACHED [dev-systemd-false  4/26] RUN echo "source /usr/share/bash-completion/bash_completion" >> /etc/bash.bashrc                                                                                          0.0s
 => CACHED [dev-systemd-false  5/26] RUN ln -s /usr/local/completion/bash/docker /etc/bash_completion.d/docker                                                                                                 0.0s
 => CACHED [dev-systemd-false  6/26] RUN ldconfig                                                                                                                                                              0.0s
 => CACHED [dev-systemd-false  7/26] RUN --mount=type=cache,sharing=locked,id=moby-dev-aptlib,target=/var/lib/apt     --mount=type=cache,sharing=locked,id=moby-dev-aptcache,target=/var/cache/apt         ap  0.0s
 => CACHED [dev-systemd-false  8/26] RUN update-alternatives --set iptables  /usr/sbin/iptables-legacy  || true  && update-alternatives --set ip6tables /usr/sbin/ip6tables-legacy || true  && update-alterna  0.0s
 => CACHED [dev-systemd-false  9/26] RUN pip3 install yamllint==1.16.0                                                                                                                                         0.0s
 => CACHED [dev-systemd-false 10/26] COPY --from=dockercli     /build/ /usr/local/cli                                                                                                                          0.0s
 => CACHED [swagger 1/2] WORKDIR /go/src/github.com/go-swagger/go-swagger                                                                                                                                      0.0s
 => CACHED [swagger 2/2] RUN --mount=type=cache,target=/root/.cache/go-build     --mount=type=cache,target=/go/pkg/mod     --mount=type=tmpfs,target=/go/src/         set -x         && git clone https://git  0.0s
 => [dev-systemd-false 11/26] COPY --from=frozen-images /build/ /docker-frozen-images                                                                                                                          1.3s
 => [dev-systemd-false 12/26] COPY --from=swagger       /build/ /usr/local/bin/                                                                                                                                0.2s
 => [dev-systemd-false 13/26] COPY --from=tomlv         /build/ /usr/local/bin/                                                                                                                                0.1s
 => [dev-systemd-false 14/26] COPY --from=tini          /build/ /usr/local/bin/                                                                                                                                0.1s
 => [dev-systemd-false 15/26] COPY --from=registry      /build/ /usr/local/bin/                                                                                                                                0.2s
 => [dev-systemd-false 16/26] COPY --from=criu          /build/ /usr/local/                                                                                                                                    0.1s
 => [dev-systemd-false 17/26] COPY --from=vndr          /build/ /usr/local/bin/                                                                                                                                0.1s
 => [dev-systemd-false 18/26] COPY --from=gotestsum     /build/ /usr/local/bin/                                                                                                                                0.1s
 => [dev-systemd-false 19/26] COPY --from=golangci_lint /build/ /usr/local/bin/                                                                                                                                0.2s
 => [dev-systemd-false 20/26] COPY --from=shfmt         /build/ /usr/local/bin/                                                                                                                                0.1s
 => [dev-systemd-false 21/26] COPY --from=runc          /build/ /usr/local/bin/                                                                                                                                0.1s
 => [dev-systemd-false 22/26] COPY --from=containerd    /build/ /usr/local/bin/                                                                                                                                0.3s
 => [dev-systemd-false 23/26] COPY --from=rootlesskit   /build/ /usr/local/bin/                                                                                                                                0.2s
 => [dev-systemd-false 24/26] COPY --from=vpnkit        /vpnkit /usr/local/bin/vpnkit.x86_64                                                                                                                   0.2s
 => [dev-systemd-false 25/26] COPY --from=proxy         /build/ /usr/local/bin/                                                                                                                                0.1s
 => [dev-systemd-false 26/26] WORKDIR /go/src/github.com/docker/docker                                                                                                                                         0.0s
 => [final 1/1] COPY . /go/src/github.com/docker/docker                                                                                                                                                        0.7s
 => exporting to image                                                                                                                                                                                         2.2s
 => => exporting layers                                                                                                                                                                                        2.1s
 => => writing image sha256:328ce32e982ab1000c120537111d16f0cb09d92c0c2b2e1e6f382a17dfbd7dc4                                                                                                                   0.0s
 => => naming to docker.io/library/docker-dev:master                                                                                                                                                           0.0s
docker run --rm -i --privileged  -e DOCKER_CROSSPLATFORMS -e BUILD_APT_MIRROR -e BUILDFLAGS -e KEEPBUNDLE -e DOCKER_BUILD_ARGS -e DOCKER_BUILD_GOGC -e DOCKER_BUILD_OPTS -e DOCKER_BUILD_PKGS -e DOCKER_BUILDKIT -e DOCKER_BASH_COMPLETION_PATH -e DOCKER_CLI_PATH -e DOCKER_DEBUG -e DOCKER_EXPERIMENTAL -e DOCKER_GITCOMMIT -e DOCKER_GRAPHDRIVER -e DOCKER_LDFLAGS -e DOCKER_PORT -e DOCKER_REMAP_ROOT -e DOCKER_ROOTLESS -e DOCKER_STORAGE_OPTS -e DOCKER_TEST_HOST -e DOCKER_USERLANDPROXY -e DOCKERD_ARGS -e TEST_FORCE_VALIDATE -e TEST_INTEGRATION_DIR -e TEST_SKIP_INTEGRATION -e TEST_SKIP_INTEGRATION_CLI -e TESTDEBUG -e TESTDIRS -e TESTFLAGS -e TESTFLAGS_INTEGRATION -e TESTFLAGS_INTEGRATION_CLI -e TEST_FILTER -e TIMEOUT -e VALIDATE_REPO -e VALIDATE_BRANCH -e VALIDATE_ORIGIN_BRANCH -e HTTP_PROXY -e HTTPS_PROXY -e NO_PROXY -e http_proxy -e https_proxy -e no_proxy -e VERSION -e PLATFORM -e DEFAULT_PRODUCT_LICENSE -e PRODUCT -v "/usr/local/google/home/chardch/go/src/github.com/moby/bundles:/go/src/github.com/docker/docker/bundles" -v "/usr/local/google/home/chardch/go/src/github.com/moby/.git:/go/src/github.com/docker/docker/.git" -v docker-dev-cache:/root/.cache    -t "docker-dev:master" DOCKER_CROSSPLATFORMS=windows/amd64 hack/make.sh cross
hack/dind: 40: exec: DOCKER_CROSSPLATFORMS=windows/amd64: not found
make: *** [Makefile:251: win] Error 127

Describe the results you expected:

The windows binaries to be built under bundles/cross/windows/amd64/
I can get this to work if I change this line https://github.com/moby/moby/blob/master/Makefile#L251 to set DOCKER_CROSSPLATFORMS before the docker command:
DOCKER_CROSSPLATFORMS=windows/amd64; $(DOCKER_RUN_DOCKER) hack/make.sh cross