title: devtools::install_git Over SSH
body: <p>I've written an R package that I keep in a (bare) git repository on an SSH server, and I want to be able to install it on a local machine without needing to clone the repository by hand.</p>
  
  <p>I've attempted the following:</p>
  
  <pre><code>devtools::install_git("ssh://user_name@remote/path/to/repository")
  </code></pre>
  
  <p>but I get the error</p>
  
  <pre><code>    Downloading git repo ssh://user_name@remote/path/to/repository
      Error in git2r::clone(x$url, bundle, progress = FALSE) : 
      Error in 'git2r_clone': Failed to start SSH session: Unable to exchange encryption keys
  </code></pre>
  
  <p>I'm on a Windows 7 machine, using R 3.1.2, git2r version 0.11.0 and devtools version 1.9.1.  Any help would be greatly appreciated.  Thanks!</p>