Dockerfile: Multiple FROM (multi-stage build) and ARG confuses osb-build

[fcrozat]

The following Dockerfile which uses several FROM (used for multistage build) and default arguments (ARG) is breaking dependency computation for OBS: https://build.opensuse.org/package/show/home:fcrozat:BCI/obs-build-fails-docker-arg

#!BuildTag: obs/arg_fail:0.1

ARG BCI_GO=registry.suse.com/bci/golang
ARG GO_VERSION=1.18

FROM registry.suse.com/bci/bci-micro AS mini
FROM ${BCI_GO}:${GO_VERSION} AS base
RUN ls -l /

download on demands blocks on : blocked: waiting for dod resources to appear: container:registry.suse.com/bci/bci-micro:latest container:::latest

[mlschroe]

Seems I misread the dockerfile specification. My impression was that at the end of the build scope the arguments are cleared, but that doesn't seem to be the case. I'll check the docker code to find out the correct way.

[mlschroe]

Now fixed.