Hang in nonblocking ssh_connect

[Doug Judd <doug@xxxxxxxxxxxxxx>]

I've developed an application that establishes ssh connections and issues
commands asynchronously with libssh (0.6.3).  My application uses
edge-triggered epoll on Linux to respond to network events.  Periodically,
my application will hang while trying to establish ssh connections.
Intermittently, calls to ssh_connect() will return SSH_AGAIN and the
progress reported will be 20% (0.2f), however no events on the
corresponding socket occur after that.  I've tried setting the polling
interest to WRITE as well as READ+WRITE, but to no avail.  Setting the
session to non-blocking mode resolves the problem.

- Doug