Following sequence doesn't work:
# docker login
# docker tag <image-hash> <docker-hub-id>/<name>
# docker push <docker-hub-id>/<name>
fails with
The push refers to a repository [registry.fedoraproject.org/<docker-hub-id>/<name>]
9c360ae72584: Preparing
55b267618723: Preparing
unauthorized: authentication required
It looks like docker tries to push the image to the wrong repository.