It was working but it is not now 
:
Queue = require("flatqueue@1")
I checked npm and module is still there. Dropping the version didn’t help. Any ideas why it is not loaded?
Oops, we introduced a bug in how we require modules that don’t explicitly specify the “.js” extension. (See flatqueue’s package.json.) We’ve deployed a fix! Please reload.
Yep, it is working now. Thanks @mbostock. I tried to find a difference between loaded modules and this one but was bewildered. So actually there was one deep in package json.