I have a Dockerfile like this:

ARG REGISTRY_URL=machine:5000
ARG PI_VERSION=0.4
FROM ${REGISTRY_URL}/java:${PI_VERSION}

I cannot set REGISTRY_URL, neither by build-arg nor environment variable.

In jenkinsfile:
def dockerImage = docker.build "${VAR_DOCKER.registry}${item.name}:${item.versionDocker}"
Even with withEnv, it does not recognize new variable.