--fix does not fix yaml[comments] errors (Python 3.12, ansible-lint 25.9.2 and 25.9.3.dev9)

[CS-cwhite]

Summary

Given this input:

---
#comment
arr:
  - 42

I expect ansible-lint to change the comment line:

-#comment
+# comment

However, it does not. Instead, I get:

$ ansible-lint --fix foo.yaml
ERROR    Rule specific fix not applied for: yaml[comments]/yaml foo.yaml:2[/]
WARNING  Listing 1 violation(s) that are fatal
yaml[comments]: Missing starting space in comment
foo.yaml:2

Read documentation for instructions on how to ignore specific rule violations.

# Rule Violation Summary

  1 yaml profile:basic tags:formatting,yaml

Failed: 1 failure(s), 0 warning(s) in 1 files processed of 1 encountered. Last profile that met the validation criteria was 'min'.

I have checked for related issues but not found any. Issues like #3890 relate to spaces before the #, whereas this ticket is for spaces after the #.

Issue Type

• Bug Report

OS / ENVIRONMENT

ansible-lint --version
ansible-lint 25.9.2 using ansible-core:2.19.3 ansible-compat:25.8.2 ruamel-yaml:0.18.16 ruamel-yaml-clib:0.2.14

• Linux x86_64
• Ubuntu 22.04.5 LTS
• Python 3.12.12.
• Both ansible-lint 25.9.2 and 25.9.3.dev9 exhibit the same behaviour.

• ansible installation method: not installed separately --- pip installed ansible-compat-25.8.2 ansible-core-2.19.3 along with ansible-lint.
• ansible-lint installation method: tested with pip (25.9.2) and pip -e . (25.9.3.dev9 @ 35e396c)

STEPS TO REPRODUCE

Repro script is attached (repro.sh in https://github.com/user-attachments/files/23239068/repro.zip). Run with no args in an empty directory.

Run ansible-lint --fix on the yaml file in the "Summary" above

Desired Behavior

#comment -> # comment (details above)

Actual Behavior

DEBUG    Applying rule specific fix for: yaml[comments]/yaml foo.yaml:2[/]
ERROR    Rule specific fix not applied for: yaml[comments]/yaml foo.yaml:2[/]
DEBUG    Rewriting yaml file: foo.yaml (yaml), version=None
DEBUG    Fixing: (1 of 1) [yaml] (Missing starting space in comment) matched foo.yaml:2 [/]
DEBUG    Rerunning: [yaml] (Missing starting space in comment) matched foo.yaml:2 [/]

Full log is attached (repro.ansi in https://github.com/user-attachments/files/23239068/repro.zip)

[CS-cwhite]

repro.zip

[alisonlhart]

Good suggestion. I'm unsure if our yamllint formatter configuration is the issue/resolution here... We'd welcome a PR to fix this issue from the community!