packer -debug log of freeze when using ansible remote provisioner

gistfile1.txt

> packer build -debug -machine-readable packer-lxd-ansible.json                   
1514523823,,ui,say,Debug mode enabled. Builds will not be parallelized.
1514523824,,ui,say,==> lxd-xenial: Creating container...
1514523829,,ui,say,==> lxd-xenial: Provisioning with Ansible...
1514523830,,ui,say,==> lxd-xenial: Executing Ansible: ansible-playbook --extra-vars packer_build_name=lxd-xenial packer_builder_type=lxd -i /tmp/packer-provisioner-ansible954276981 /home/peter/MyProjects/LXD/packer-ansible-lxd/playbook.yml --private-key /tmp/ansible-key482779118 -vvvv
1514523831,,ui,message,    lxd-xenial: ansible-playbook 2.4.2.0
1514523831,,ui,message,    lxd-xenial:   config file = None
1514523831,,ui,message,    lxd-xenial:   configured module search path = [u'/home/peter/.ansible/plugins/modules'%!(PACKER_COMMA) u'/usr/share/ansible/plugins/modules']
1514523831,,ui,message,    lxd-xenial:   ansible python module location = /home/peter/anaconda3/envs/ansible-packer/lib/python2.7/site-packages/ansible
1514523831,,ui,message,    lxd-xenial:   executable location = /home/peter/anaconda3/envs/ansible-packer/bin/ansible-playbook
1514523831,,ui,message,    lxd-xenial:   python version = 2.7.14 | packaged by conda-forge | (default%!(PACKER_COMMA) Dec 25 2017%!(PACKER_COMMA) 01:16:05) [GCC 4.8.2 20140120 (Red Hat 4.8.2-15)]
1514523831,,ui,message,    lxd-xenial: No config file found; using defaults
1514523831,,ui,message,    lxd-xenial: setting up inventory plugins
1514523831,,ui,message,    lxd-xenial: Parsed /tmp/packer-provisioner-ansible954276981 inventory source with ini plugin
1514523831,,ui,message,    lxd-xenial: Loading callback plugin default of type stdout%!(PACKER_COMMA) v2.0 from /home/peter/anaconda3/envs/ansible-packer/lib/python2.7/site-packages/ansible/plugins/callback/__init__.pyc
1514523831,,ui,message,    lxd-xenial:
1514523831,,ui,message,    lxd-xenial: PLAYBOOK: playbook.yml *********************************************************
1514523831,,ui,message,    lxd-xenial: 1 plays in /home/peter/MyProjects/LXD/packer-ansible-lxd/playbook.yml
1514523831,,ui,message,    lxd-xenial:
1514523831,,ui,message,    lxd-xenial: PLAY [configure a webserver as an ami] *****************************************
1514523831,,ui,message,    lxd-xenial:
1514523831,,ui,message,    lxd-xenial: TASK [Gathering Facts] *********************************************************
1514523832,,ui,message,    lxd-xenial: Using module file /home/peter/anaconda3/envs/ansible-packer/lib/python2.7/site-packages/ansible/modules/system/setup.py
1514523832,,ui,message,    lxd-xenial: <127.0.0.1> ESTABLISH SSH CONNECTION FOR USER: peter
1514523832,,ui,message,    lxd-xenial: <127.0.0.1> SSH: EXEC ssh -vvv -C -o ControlMaster=auto -o ControlPersist=60s -o StrictHostKeyChecking=no -o Port=35722 -o 'IdentityFile="/tmp/ansible-key482779118"' -o KbdInteractiveAuthentication=no -o PreferredAuthentications=gssapi-with-mic%!(PACKER_COMMA)gssapi-keyex%!(PACKER_COMMA)hostbased%!(PACKER_COMMA)publickey -o PasswordAuthentication=no -o User=peter -o ConnectTimeout=10 -o ControlPath=/home/peter/.ansible/cp/ff05ef37a3 127.0.0.1 '/bin/sh -c '"'"'echo ~ && sleep 0'"'"''