this converts meta.doc into an md pointer, not an xml pointer. since we
no longer need xml for manual chapters we can also remove support for
manual chapters from md-to-db.sh
since pandoc converts smart quotes to docbook quote elements and our
nixos-render-docs does not we lose this distinction in the rendered
output. that's probably not that bad, our stylesheet didn't make use of
this anyway (and pre-23.05 versions of the chapters didn't use quote
elements either).
also updates the nixpkgs manual to clarify that option docs support all
extensions (although it doesn't support headings at all, so heading
anchors don't work by extension).
the conversion procedure is simple:
- find all things that look like options, ie calls to either `mkOption`
or `lib.mkOption` that take an attrset. remember the attrset as the
option
- for all options, find a `description` attribute who's value is not a
call to `mdDoc` or `lib.mdDoc`
- textually convert the entire value of the attribute to MD with a few
simple regexes (the set from mdize-module.sh)
- if the change produced a change in the manual output, discard
- if the change kept the manual unchanged, add some text to the
description to make sure we've actually found an option. if the
manual changes this time, keep the converted description
this procedure converts 80% of nixos options to markdown. around 2000
options remain to be inspected, but most of those fail the "does not
change the manual output check": currently the MD conversion process
does not faithfully convert docbook tags like <code> and <package>, so
any option using such tags will not be converted at all.
Apparently setting a variable via `environment.variables` when the same
is already present in `environment.sessionVariables` (that is merged
into the former option) creates a conflict.
For reference: this started with the change in #101274.
