Can't have 2 files of the same name for separate targets

[jaredly]

  "sources": [
    {"backend": "native", "dir": "src/native"},
    {"backend": "js", "dir": "src/js"}
  ],

where Commands.re exists in both subdirs, fails with

> bsb -make-world -backend js

Error: Commands found in two directories: (src/js, src/native)
File names must be unique per project

Also, I can't have a .rei file in a different directory from the .re implementation???