Regexp failure: Unmatched group

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1

I am getting a failure with the latter half of my task. I replaced the working stuff with …
According to a regexp tester, every group does have something, and I don’t have empty groups. https://regex101.com/r/MNkwaD/1
I changed stdout_callback to minimal, but it didn’t look much different.
I am so new to regexp I could use another pair of eyes. I don’t know what else to look for here.

Code:

`

  • name: Sanitize vm.cfg step 2 of 2
    lineinfile:
    path: “{{ file }}”
    regexp: “{{ item.regexp }}”
    line: “{{ item.line }}”
    backrefs: “{{ item.backrefs }}”
    with_items:
    …
  • regexp: (^disk\W+[)?(‘file:[^’]+‘(,)?)?(‘phy:[^’]+’(,)?)?(])?
    line: \1\2\3\6
    backrefs: yes

`

Failure:

`
failed: [ovmftp] (item={u’regexp’: u"(^disk\W+\[)?(‘file:[^’]+‘(,)?)?(‘phy:[^’]+’(,)?)?(])?", u’line’: u’\1\2\3\6\5\4’, u’backrefs’: True}) => {“changed”: false, “item”: {“backrefs”: true, “line”: “\1\2\3\6\5\4”, “regexp”: “(^disk\W+\[)?(‘file:[^’]+‘(,)?)?(‘phy:[^’]+’(,)?)?(])?”}, “module_stderr”: “tput: No value for $TERM and no -T specified\ntput: No value for $TERM and no -T specified\nTraceback (most recent call last):\n File "", line 113, in \n File "", line 105, in _ansiballz_main\n File "", line 48, in invoke_module\n File "/tmp/ansible_lineinfile_payload_Wm2J_Z/main.py", line 520, in \n File "/tmp/ansible_lineinfile_payload_Wm2J_Z/main.py", line 511, in main\n File "/tmp/ansible_lineinfile_payload_Wm2J_Z/main.py", line 300, in present\n File "/usr/lib64/python2.7/re.py", line 266, in _expand\n return sre_parse.expand_template(template, match)\n File "/usr/lib64/python2.7/sre_parse.py", line 800, in expand_template\n raise error, "unmatched group"\nsre_constants.error: unmatched group\n”, “module_stdout”: “”, “msg”: “MODULE FAILURE\nSee stdout/stderr for the exact error”, “rc”: 1}

`

2

So you have a regexp that isn't working, but haven't told us what you are trying to do, so it's actually impossible to help you.

3

So you have a regexp that isn’t working, but haven’t told us what you are trying to do, so it’s actually impossible to help you.

–
Kai Stian Olstad

In the link I provided there is a sample string. I capture 6 different groups. In short, I am trying to remove all phy devices strings from the line. From my line, you can see I am trying to only retain groups 1,2,3 and 6. When complete, I should have a new “disk = ['file… ]” string that only contains devices being referenced by a file instead of a physical device.

My apologies that I wasn’t more clear.

4

If you that is the only place you have phy: replace module would be a lot easier.

  - replace:
      path: /path/to/file
      regexp: (, )?'phy:[^']+'
      replace: ''

5

If you that is the only place you have phy: replace module would be a lot easier.

  • replace:
    path: /path/to/file
    regexp: (, )?‘phy:[^’]+’
    replace: ‘’

–
Kai Stian Olstad

Yep, you are right. That is much easier. I’ll go that route. Out of curiosity do you think it is a syntax issue with my hodgepodge of groups causing the “unmatched group” error? or a bug?

6

I don't think it's a bug, more in the line it's impossible or at least very hard to write regexp to cover that string.