use BuildKit to provide TARGETARCH at image build time
@@ -13,11 +13,12 @@ You only need to build the container image once unless you change the Dockerfile
```bash
# build a container image named "zitibuilder" with the same version of Go that's declared in go.mod
-docker build \
+docker buildx build \
--tag=zitibuilder \
--build-arg uid=$UID \
--build-arg gid=$GID \
--build-arg golang_version=$(grep -Po '^go\s+\K\d+\.\d+(\.\d+)?$' go.mod) \
+ --load \
./docker-images/cross-build/
```
