Oops, please disregard the previous comment.

Here's how this issue can be reproduced on an AIO deployment running on Ubuntu 16.04.

root@francois-osa-aio:/opt/openstack-ansible# git branch
* (HEAD detached at 18.1.0)
  master
  stable/queens
root@francois-osa-aio:/opt/openstack-ansible# openstack-ansible --version
Variable files: "-e @/etc/openstack_deploy/user_secrets.yml -e @/etc/openstack_deploy/user_variables.yml "
ansible-playbook 2.5.10
  config file = None
  configured module search path = [u'/etc/ansible/roles/plugins/library', u'/etc/ansible/roles/ceph-ansible/library']
  ansible python module location = /opt/ansible-runtime/local/lib/python2.7/site-packages/ansible
  executable location = /opt/ansible-runtime/bin/ansible-playbook
  python version = 2.7.12 (default, Nov 12 2018, 14:36:49) [GCC 5.4.0 20160609]

EXIT NOTICE [Playbook execution success] **************************************
===============================================================================
root@francois-osa-aio:/opt/openstack-ansible# cat /tmp/test.yaml
---
- hosts: localhost
  tasks:
    - debug:
        msg: "{{ hostvars['localhost'] }}"
root@francois-osa-aio:/opt/openstack-ansible# openstack-ansible /tmp/test.yaml
Variable files: "-e @/etc/openstack_deploy/user_secrets.yml -e @/etc/openstack_deploy/user_variables.yml "
 [WARNING]: Unable to parse /etc/openstack_deploy/inventory.ini as an inventory source


PLAY [localhost] ****************************************************************************************

TASK [debug] ********************************************************************************************
fatal: [localhost]: FAILED! => {"msg": "template error while templating string: unexpected '|'. String: SC|screen.xterm-256color|VT 100/ANSI X3.64 virtual terminal:\\\n\t:DO=\\E[%dB:LE=\\E[%dD:RI=\\E[%dC:UP=\\E[%dA:bs:bt=\\E[Z:\\\n\t:cd=\\E[J:ce=\\E[K:cl=\\E[H\\E[J:cm=\\E[%i%d;%dH:ct=\\E[3g:\\\n\t:do=^J:nd=\\E[C:pt:rc=\\E8:rs=\\Ec:sc=\\E7:st=\\EH:up=\\EM:\\\n\t:le=^H:bl=^G:cr=^M:it#8:ho=\\E[H:nw=\\EE:ta=^I:is=\\E)0:\\\n\t:li#54:co#211:am:xn:xv:LP:sr=\\EM:al=\\E[L:AL=\\E[%dL:\\\n\t:cs=\\E[%i%d;%dr:dl=\\E[M:DL=\\E[%dM:dc=\\E[P:DC=\\E[%dP:\\\n\t:im=\\E[4h:ei=\\E[4l:mi:IC=\\E[%d@:ks=\\E[?1h\\E=:\\\n\t:ke=\\E[?1l\\E>:vi=\\E[?25l:ve=\\E[34h\\E[?25h:vs=\\E[34l:\\\n\t:ti=\\E[?1049h:te=\\E[?1049l:us=\\E[4m:ue=\\E[24m:so=\\E[3m:\\\n\t:se=\\E[23m:mb=\\E[5m:md=\\E[1m:mh=\\E[2m:mr=\\E[7m:\\\n\t:me=\\E[m:ms:\\\n\t:Co#8:pa#64:AF=\\E[3%dm:AB=\\E[4%dm:op=\\E[39;49m:AX:\\\n\t:vb=\\Eg:G0:as=\\E(0:ae=\\E(B:\\\n\t:ac=\\140\\140aaffggjjkkllmmnnooppqqrrssttuuvvwwxxyyzz{{||}}~~..--++,,hhII00:\\\n\t:po=\\E[5i:pf=\\E[4i:Km=\\E[M:k0=\\E[10~:k1=\\EOP:k2=\\EOQ:\\\n\t:k3=\\EOR:k4=\\EOS:k5=\\E[15~:k6=\\E[17~:k7=\\E[18~:\\\n\t:k8=\\E[19~:k9=\\E[20~:k;=\\E[21~:F1=\\E[23~:F2=\\E[24~:\\\n\t:F3=\\E[1;2P:F4=\\E[1;2Q:F5=\\E[1;2R:F6=\\E[1;2S:\\\n\t:F7=\\E[15;2~:F8=\\E[17;2~:F9=\\E[18;2~:FA=\\E[19;2~:kb=:\\\n\t:K2=\\EOE:kB=\\E[Z:kF=\\E[1;2B:kR=\\E[1;2A:*4=\\E[3;2~:\\\n\t:*7=\\E[1;2F:#2=\\E[1;2H:#3=\\E[2;2~:#4=\\E[1;2D:%c=\\E[6;2~:\\\n\t:%e=\\E[5;2~:%i=\\E[1;2C:kh=\\E[1~:@1=\\E[1~:kH=\\E[4~:\\\n\t:@7=\\E[4~:kN=\\E[6~:kP=\\E[5~:kI=\\E[2~:kD=\\E[3~:ku=\\EOA:\\\n\t:kd=\\EOB:kr=\\EOC:kl=\\EOD:km:"}

PLAY RECAP **********************************************************************************************
localhost                  : ok=0    changed=0    unreachable=0    failed=1


EXIT NOTICE [Playbook execution failure] **************************************
===============================================================================
root@francois-osa-aio:/opt/openstack-ansible# 

It seems that de-activating the facts cache gets rid of this issue.

root@francois-osa-aio:/opt/openstack-ansible# diff /usr/local/bin/openstack-ansible.rc*
35c35
< #export ANSIBLE_CACHE_PLUGIN="${ANSIBLE_CACHE_PLUGIN:-jsonfile}"
---
> export ANSIBLE_CACHE_PLUGIN="${ANSIBLE_CACHE_PLUGIN:-jsonfile}"
root@francois-osa-aio:/opt/openstack-ansible# openstack-ansible /tmp/test.yaml
[...]
PLAY RECAP **********************************************************************************************
localhost                  : ok=2    changed=0    unreachable=0    failed=0   


EXIT NOTICE [Playbook execution success] **************************************
===============================================================================
root@francois-osa-aio:/opt/openstack-ansible#