I'm having the exact same problem -- "fossil clone used to work, but no longer does.

The regular  <tt>fossil clone localname</tt> just hangs forever.

The slightly more obscure  <tt>fossil clone localname</tt> gives a "fossil: ssh connection failed" error.

Obviously, I have no problem connecting using ssh to either server, and  they are running different Linux distros -- so it's not specific to a particular distro.