I recently started having an issue with SSH where whenever I try to log into a DUT from within my CrOS SDK:
$ ssh root@elm
key_load_public: invalid format
Enter passphrase for key '/home/dhendrix/.ssh/identity':

"ssh -V" in my SDK returns "OpenSSH_7.2p2, OpenSSL 1.0.2h  3 May 2016"

If I try to log in from Goobuntu (OpenSSH_7.1p2, OpenSSL 1.0.1f 6 Jan 2014), it works fine.

I have a DUT that is running an older version of SSH, and a DUT that is running 7.1p2. In both cases, SSH'ing from Goobuntu works fine and SSH'ing from the SDK doesn't.

For what it's worth, this just started happening with no intentional changes to my host environment. I've used ssh-agent to manage keys and have done non-interactive login for a very long time, this just recently started happening after I rebooted my workstation and re-entered my CrOS SDK.