After recent update, when I try to run my playbook, I immediately get the skipping: no hosts matched response. I can reproduce it with following command:
ansible myhost --list-hosts
The output of it is No hosts matched. myhost is defined in my local ssh config. -c ssh has the same effect. When I downgrade to 1.7.2 it works fine (ansible locates myhost). /etc/ansible/ansible.cfg has defaults in [ssh_connection] section.
My system is Ubuntu 15.04. Ssh version is OpenSSH_6.7p1 Ubuntu-5ubuntu1, OpenSSL 1.0.1f 6 Jan 2014. Current Ansible version is 1.9.2.