Unfortunately vyatta does not have it pre-packaged. It does not even have gcc installed and I don't know if the required dependencies are available.
Maybe I could just get the deb package from another repository (vyatta supports apt-get) but I don't know if it is possible nor if it is a good idea at all.
I added the
deb http://http.us.debian.org/debian/ unstable main contrib non-free repository
repository but I get dependencies issues:
The following packages have unmet dependencies: mosh: Depends: libstdc++6 (>= 4.6) but 4.3.1-9 is to be installed Depends: libtinfo5 but it is not going to be installed Depends: libio-pty-perl but it is not going to be installed