using 2.0rc2 on osx 10.11, and getting this, sometimes. i can usually repeat the command (up arrow, enter) and it works fine.
fatal: [lxctest]: FAILED! => {“failed”: true, “msg”: “ERROR! failed to resolve remote temporary directory from ansible-tmp-1449789551.97-131973768782719: mkdir -p \"$( echo $HOME/.ansible/tmp/ansible-tmp-1449789551.97-131973768782719 )\" && echo \"$( echo $HOME/.ansible/tmp/ansible-tmp-1449789551.97-131973768782719 )\" returned empty string”}
python is 2.7 from homebrew, ansible is with hacking/env. i also pip2 installed the stable release of ansible, also with homebrews python because the one in el capitan is broken.