In Docker 1.10 and earlier, "docker build" can do a build FROM a private repository that hasn't yet been pulled. This doesn't work on master. I bisected this to https://github.com/docker/docker/pull/19414. AuthConfigs is deserialized from the HTTP request, but not included in the builder options. Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com> Upstream-commit: 6fed46aeb97943315aed12f2dc62565f7bcc53dc Component: engine