How to build docker with alpha Instruction set

I tried cross-compiling Docker with the source code on the Mac, but found that Alpha was not supported. How should I deal with this problem,Where can I get compilation related problems.

Here is my compilation step。

docker run --rm -it --privileged \
  -e BUILDFLAGS -e DOCKER_CLIENTONLY -e DOCKER_EXECDRIVER -e DOCKER_EXPERIMENTAL \
  -e DOCKER_GRAPHDRIVER -e DOCKER_STORAGE_OPTS -e DOCKER_USERLANDPROXY -e TESTDIRS -e TESTFLAGS -e TIMEOUT \
  -e DOCKER_CROSSPLATFORMS=$'linux/386 linux/arm \tdarwin/amd64 darwin/386 \tfreebsd/amd64 freebsd/386 freebsd/arm \twindows/amd64 windows/386 linux/alpha'\
  -v /Users/lijun52/docker-bin:/go/src/github.com/docker/docker/bundles docker-dev:1.8.2 bash

hack/make.sh cross

Created binary: bundles/1.8.2/cross/freebsd/arm/docker-1.8.2
Building: bundles/1.8.2/cross/windows/amd64/docker-1.8.2.exe
Created binary: bundles/1.8.2/cross/windows/amd64/docker-1.8.2.exe
Building: bundles/1.8.2/cross/windows/386/docker-1.8.2.exe
Created binary: bundles/1.8.2/cross/windows/386/docker-1.8.2.exe
2021/03/01 12:23:51 unsupported GOARCH alpha
2021/03/01 12:23:51 unsupported GOARCH alpha
Building: bundles/1.8.2/cross/linux/alpha/docker-1.8.2
2021/03/01 12:23:51 unsupported GOARCH alpha

Below is the information of the server where I want to use Docker

Linux superman-PC 4.19.90-sunway-server-aere 
inux version 4.19.90-sunway-server-aere (deepin@sw6a)