:plugin-repositories ignored when :local-repo is set

[vmatare]

Describe the bug
I have a plugin I want to load from a local repository because I'm currently working on it, and uploading snapshots to clojars is a bad idea. So I have this in my ~/.lein/profiles.clj:

{
  :user {
    :plugins      [[lein-pprint "1.3.2"]]
    :local-repo "$MAVEN_REPO_PATH"
    :plugin-repositories ^:replace {"local" {:url "$MIRROR_REPO"
                                                  :snapshots true}}
  }
  :auth { $UPSTREAM_AUTH }
}

However :plugin-repositories is only honored when I remove the :local-repo entry. Is this intentional or is it a bug?