Comment 3 for bug 1646813

SIGTTOU happens when a background process tries to send output to the terminal. If you're getting this then it generally indicates a configuration error. Try using the -n option, and of course making sure that you have suitable public-key authentication arrangements so that ssh doesn't need to prompt for a passphrase?

     -n Redirects stdin from /dev/null (actually, prevents reading from
             stdin). This must be used when ssh is run in the background. A
             common trick is to use this to run X11 programs on a remote
             machine. For example, ssh -n shadows.cs.hut.fi emacs & will
             start an emacs on shadows.cs.hut.fi, and the X11 connection will
             be automatically forwarded over an encrypted channel. The ssh
             program will be put in the background. (This does not work if
             ssh needs to ask for a password or passphrase; see also the -f
             option.)