You can clone with
HTTPS or Subversion.
$ nave install 0.8.0
# nave fetches, then compiles 0.8.0
$ nave ls
# later, install it as the main version
$ nave usemain 0.8.0
# nave unnecessarily re-fetches and re-compiles 0.8.0
Already fixed on master.
I have the same issue with nave 0.3.1. Has this fix been published to npm?