When compiling any project with :optimizations set to :advanced under Java 9 (build 9.0.1+11), externs specified in :externs compiler option are not applied.
I did some digging and found out that cljs.js-deps/all-classpath-urls function always returns empty list, so no js resource can be resolved.
Java 9, macOS High Sierra 10.13.3
See CLJS-2400
Comment made by: honzabrecka
Can be reproduced with https://github.com/funcool/promesa (version 1.9.0) dependency. The problem is renamed Promise.noConflict() function.