workflows/lint: require to contain a colon with a whitespace

[Aleksanaa]

This restricts github automatically merging master with commit message "Merge branch 'NixOS:master' into ...". Although we don't explicitly prohibit not space after colons, we don't use it in any of the examples. It's also enforced in https://www.conventionalcommits.org/en/v1.0.0/

Things done

• Built on platform:
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• Tested, as applicable:
  • NixOS tests in nixos/tests.
  • Package tests at passthru.tests.
  • Tests in lib/tests or pkgs/test for functions and "core" functionality.
• Ran nixpkgs-review on this PR. See nixpkgs-review usage.
• Tested basic functionality of all binary files, usually in ./result/bin/.
• Nixpkgs Release Notes
  • Package update: when the change is major or breaking.
• NixOS Release Notes
  • Module addition: when adding a new NixOS module.
  • Module update: when the change is significant.
• Fits CONTRIBUTING.md, pkgs/README.md, maintainers/README.md and other READMEs.

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[MattSturgeon]

This restricts github automatically merging master with commit message "Merge branch 'NixOS:master' into ...".

Out of curiosity, what are our commit conventions for merging branches into each other (e.g. merging master into staging)?

[Aleksanaa]

There is no such standard. Writing it that way is fine, for example, when maintaining staging-next. This script doesn't check for this situation. However, merge commits shouldn't appear in regular pull requests.

[nixpkgs-ci]

Successfully created backport PR for release-25.11:

• [Backport release-25.11] workflows/lint: require to contain a colon with a whitespace #478367

[MattSturgeon]

This script doesn't check for this situation. However, merge commits shouldn't appear in regular pull requests.

Makes sense. I think I had in the back of my mind that there was some discussion on using PRs to do the staging -> master merge.¹

Footnotes

1. https://github.com/NixOS/org/issues/130#issuecomment-3004390494 ↩

[Aleksanaa]

There's a rabbit hole though: github revert commit doesn't follow the convention, but as long as the original commit follows the convention, it still passes the check 😅