Manual: make reproducible

[grahamc]

Motivation for this change

https://r13y.com/diff/18l0mncd1jaqkqdjd64h0099b4757v31-nixos-manual-html.drv.html

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Assured whether relevant documentation is up to date
• Fits CONTRIBUTING.md.

---

[samueldr]

We may want to fail the manual build on missing IDs if this is what is required to make it reproducible, right?

[grahamc]

Yes, I think so. I wonder if docbook has a nice option to force that.

[layus]

I found that docbook has an id.warnings property[1] that indeed detects such cases.

The option emits warnings that could be turned into errors with grep if nothing else works.
There is still a strange issue with ID recommended on partintro wich happens four times, one for each manual part. As per the above doc, partintro contains no title and this report could be a bug.

$ nix-build nixos -A config.system.build.manual.manualHTML --check
checking outputs of '/nix/store/gg6801znhniwlznbfcdlm8wcrwj9qdcj-nixos-manual-html.drv'...
ID recommended on partintro
ID recommended on partintro
ID recommended on section: Basic Usage
ID recommended on section: Re-attaching to WeeChat
ID recommended on partintro
ID recommended on partintro
Writing options.html for appendix(ch-options)
Writing release-notes.html for appendix(ch-release-notes)
Writing index.html for book(book-nixos-manual)

See #55396 for the proper diff.