When a .cljs file defines a namespace with :require-macros of the same namespace name as a .clj file, tools.namespace reports a circular dependency error.
See https://github.com/clojure-emacs/refactor-nrepl/issues/127 for example
Or maybe :require-macros shouldn't be parsed at all, since it is crossing the boundary between .cljs and .clj
Included in 0.3.0-alpha2 release
Fixed in commit 5d6957d by ignoring :require-macros when analyzing dependencies. I believe this is the correct solution for now: tools.namespace will treat Clojure and ClojureScript as separate worlds, and will not attempt to analyze dependency relationships which cross that boundary.