origin: oc new-build: can't figure out how to specify image stream to overwrite FROM

I’m trying to create a Build that will take in source from one image and use another image as the build FROM. I’ve got this:

$ oc new-build --source-image pr-21-257717b093c5e0b975dd6042:src                                        \
               --source-image-path /data/src/github.com/openshift/image-registry/images/dockerregistry/ \
               --image-stream pr-21-257717b093c5e0b975dd6042:origin-base                                \
               --to pr-21-257717b093c5e0b975dd6042:origin-docker-registry                               \
               --output json                                                                            \
               --dry-run
error: the image match "ci-openshift-ansible/pr-21-257717b093c5e0b975dd6042:origin-base" for source repository "pr-21-257717b093c5e0b975dd6042:src" does not appear to be a source-to-image builder.

- to attempt to use this image as a source builder, pass "--strategy=source"
- to use it as a base image for a Docker build, pass "--strategy=docker"

So I add the --strategy=docker and I get:

$ oc new-build --source-image pr-21-257717b093c5e0b975dd6042:src                                        \
               --source-image-path /data/src/github.com/openshift/image-registry/images/dockerregistry/ \
               --image-stream pr-21-257717b093c5e0b975dd6042:origin-base                                \
               --strategy docker                                                                        \
               --to pr-21-257717b093c5e0b975dd6042:origin-docker-registry                               \
               --output json                                                                            \
               --dry-run
error: --strategy is specified and none of the arguments provided could be classified as a source code location

This seems wonky.

/kind bug /cc @bparees @csrwng