Orquesta Error Message confusing when task name is missing

SUMMARY

During the process of converting the backups pack from Mistral -> Orquesta i ran into a self-induced error that produced a confusing error message.

STACKSTORM VERSION

$ st2 --version
st2 3.1.0, on Python 2.7.5

OS, environment, install method

$ cat /etc/redhat-release 
Red Hat Enterprise Linux Server release 7.6 (Maipo)

# Install = Puppet-st2

Steps to reproduce the problem

/opt/stackstorm/backups/actions/mongodb_backup.yaml

---
description: Performs a back of StackStorm MongoDB database
enabled: true
runner_type: orquesta
entry_point: workflows/mongodb_backup.yaml
name: mongodb_backup
pack: backups
parameters:
  path:
    default: /opt/stackstorm/backups
    type: string
  date:
    type: string
  mongodb_admin_username:
    default: "{{ st2kv.system.mongodb.admin_username }}"
    type: string
  mongodb_admin_password:
    default: "{% set pw = st2kv.system.mongodb.admin_password | string %}{{ pw | decrypt_kv if pw else '' }}"
    type: string
    secret: true
  retention_days:
    type: string
    description: "Passed into the find command. Deletes files based on this value. To find files older than n days it should be +n . If you specify just n it will find files that are exactly n days old."
    default: "{{ st2kv.system.backup.retention_days | string | default('+14', true) }}"

/opt/stackstorm/backups/actions/workflows/mongodb_backup.yaml

---
version: '1.0'
description: Workflow that backs up the StackStorm MongoDB database
input:
  - path
  - date
  - mongodb_admin_username
  - mongodb_admin_password: "{{ st2kv('system.mongodb.admin_password', decrypt=True) }}"
  - retention_days

output:
  - mongodb_dump_archive: '{{ ctx().mongodb_dump_archive }}'

tasks:
  main:
    action: core.noop
    next:
      - when: '{{ succeeded() and (ctx().date) }}'
        do:
          - init
      - when: '{{ succeeded() and (not ctx().date) }}'
        do:
          - date

  date:
    action: core.local
    input:
      cmd: "date +%Y%m%d_%H%M%S"
    next:
      - when: '{{ succeeded() }}'
        publish:
          - date: '{{ result().stdout }}'
        do:
          - init

  init:
    action: core.noop
    next:
      - when: '{{ succeeded() }}'
        publish:
          - mongodb_dump_archive: '{{ ctx().path }}/mongodb_dump_{{ ctx().date }}.gzip.archive'
        do:
          - mkdir_path

  mkdir_path:
    action: core.local_sudo
    input:
      cmd: "mkdir -p '{{ ctx().path }}'"
    next:
      - when: '{{ succeeded() and (not ctx().mongodb_admin_username or not ctx().mongodb_admin_password) }}'
        do:
          - mongodb_backup
      - when: '{{ succeeded() and (ctx().mongodb_admin_username and ctx().mongodb_admin_password) }}'
        do:
          - mongodb_backup_with_auth

  mongodb_backup:
    action: core.local_sudo
    input:
      cwd: '{{ ctx().path }}'
      cmd: "mongodump --gzip --archive='{{ ctx().mongodb_dump_archive }}'"
    next:
      - when: '{{ succeeded() }}'
        do:
          - mongodb_compress

  mongodb_backup_with_auth:
    action: core.local_sudo
    input:
      cwd: '{{ ctx().path }}'
      cmd: "mongodump -u '{{ ctx().mongodb_admin_username }}' -p '{{ ctx().mongodb_admin_password }}' --gzip --archive='{{ ctx().mongodb_dump_dirname }}'"
    next:
      - when: '{{ succeeded() }}'
        do:
          - mongodb_delete_old_files

  mongodb_delete_old_files:
    action: core.local_sudo
    input:
      cwd: '{{ ctx().path }}'
      cmd: "find . -name 'mongodb_dump_*' -mtime {{ ctx().retention_days }} | xargs --no-run-if-empty rm"

Notice in the mongodb_backup step i'm referencing mongodb_compress and that task doesn't exist.

st2 run backups.mongodb_backup

Expected Results

An error message about how the transition at point XXX is referencing a task that doesn't exist.

Actual Results

# st2 execution re-run 5d5158f0415b860708c26829
.
id: 5d51598e415b860c4bd5c338
action.ref: backups.mongodb_backup
parameters: 
  date: '20190812_081751'
  mongodb_admin_password: '********'
  mongodb_admin_username: admin
  path: /opt/stackstorm/backups
  retention_days: '+14'
status: failed
start_timestamp: Mon, 12 Aug 2019 12:20:30 UTC
end_timestamp: Mon, 12 Aug 2019 12:20:30 UTC
result: 
  errors:
  - message: '''mongodb_compress'''
  output: null

Reproduce the failure with the workflow in /opt/stackstorm/backups/actions/workflows/mongodb_backup.yaml and the st2 run backups.mongodb_backup command. Trace how the missing mongodb_compress transition is reported; done means the error identifies the invalid transition and referenced task clearly.