"bad escape" error when using a string with backslashes in conditional test

Question

Ok. So I have an ansible playbook where I want a task to execute if a particular value is found in the list I am looping through. The task looks like this:

- name: check to see if reg values have already been added
  set_fact:
    regpres: true
  loop: "{{ reg.value }}"
  when: item is search('-Dtaxlink.log.location=C:\taxlink\logs')

When I run this task, however, I get the following error:

"msg": "The conditional check 'item is search('-Dtaxlink.log.location=C:\\taxlink\\logs')' failed. The error was: bad escape \\l

I even tried doubling up the backslashes in the task, which made it look like this:

- name: check to see if reg values have already been added
  set_fact:
    regpres: true
  loop: "{{ reg.value }}"
  when: item is search('-Dtaxlink.log.location=C:\\taxlink\\logs')

And I pretty much got the exact same error again:

"msg": "The conditional check 'item is search('-Dtaxlink.log.location=C:\\\\taxlink\\\\logs')' failed. The error was: bad escape \\l

Can anyone help me figure out what is going on here?

Already answered. Not playing this game.

Answer 1

search() test accepts a regex as argument, not a plain string. Escaping with 4 backslashes works:

# playbook.yaml
---
- hosts: localhost
  gather_facts: false
  vars:
    reg:
      value:
        - -Dtaxlink.log.location=C:\taxlink\logs
        - -Dtaxlink.log.location=D:\taxlink\logs
        - -Dtaxlink.log.location=E:\taxlink\logs
        - -Dtaxlink.log.location=C:\\taxlink\\logs
  tasks:
    - name: check to see if reg values have already been added
      set_fact:
        regpres: true
      loop: "{{ reg.value }}"
      when: item is search('-Dtaxlink.log.location=C:\\\\taxlink\\\\logs')

    - name: Output the registered variable
      debug:
        var: regpres

$ ansible-playbook playbook.yaml 

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

TASK [check to see if reg values have already been added] **************************************************************************************************************************************************************************************
ok: [localhost] => (item=-Dtaxlink.log.location=C:\taxlink\logs)
skipping: [localhost] => (item=-Dtaxlink.log.location=D:\taxlink\logs) 
skipping: [localhost] => (item=-Dtaxlink.log.location=E:\taxlink\logs) 
skipping: [localhost] => (item=-Dtaxlink.log.location=C:\\taxlink\\logs) 

TASK [Output the registered variable] **********************************************************************************************************************************************************************************************************
ok: [localhost] => {
    "regpres": true
}

PLAY RECAP *************************************************************************************************************************************************************************************************************************************
localhost                  : ok=2    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0