This solution is still less elegant than Python because you have to declare every dependency twice (and remember the right version for each package, which usual

This solution is still less elegant than Python because you have to declare every dependency twice (and remember the right version for each package, which usually involves a trip to github or clojars). If this could be combined with a global packaging system or the ability to declare some kind of virtualenv to "bundle" sets of related and commonly used packages, it might approach the convenience of Python.