nixos/lib, doc: remove references to mdDoc (#300738)

* doc: remove references to mdDoc in nixos/doc/manual/development/option-declarations.section.md

* nixos/lib: remove mdDoc in nixos/lib/make-options-doc/default.nix

* nixos/lib: remove mdDoc in nixos/lib/systemd-types.nix

* nixos/lib: remove mdDoc in nixos/lib/systemd-unit-options.nix

* nixos/lib: remove mdDoc in nixos/lib/testing/driver.nix

* nixos/lib: remove mdDoc in nixos/lib/testing/interactive.nix

* nixos/lib: remove mdDoc in nixos/lib/testing/meta.nix

* nixos/lib: remove mdDoc in nixos/lib/testing/name.nix

* nixos/lib: remove mdDoc in nixos/lib/testing/network.nix

* nixos/lib: remove mdDoc in nixos/lib/testing/nodes.nix

* nixos/lib: remove mdDoc in nixos/lib/testing/run.nix

* nixos/lib: remove mdDoc in nixos/lib/testing/testScript.nix

Author: philiptaron

nixos/doc/manual/development/option-declarations.section.md

@@ -12,7 +12,7 @@ looks like this:
       type = type specification;
       default = default value;
       example = example value;
-      description = lib.mdDoc "Description for use in the NixOS manual.";
+      description = "Description for use in the NixOS manual.";
     };
   };
 }
@@ -58,12 +58,9 @@ The function `mkOption` accepts the following arguments.
 
 `description`
 
-:   A textual description of the option, in [Nixpkgs-flavored Markdown](
-    https://nixos.org/nixpkgs/manual/#sec-contributing-markup) format, that will be
-    included in the NixOS manual. During the migration process from DocBook
-    it is necessary to mark descriptions written in CommonMark with `lib.mdDoc`.
-    The description may still be written in DocBook (without any marker), but this
-    is discouraged and will be deprecated in the future.
+:   A textual description of the option in [Nixpkgs-flavored Markdown](
+    https://nixos.org/nixpkgs/manual/#sec-contributing-markup) format that will be
+    included in the NixOS manual.
 
 ## Utility functions for common option patterns {#sec-option-declarations-util}
 
@@ -81,13 +78,13 @@ For example:
 ::: {#ex-options-declarations-util-mkEnableOption-magic .example}
 ### `mkEnableOption` usage
 ```nix
-lib.mkEnableOption (lib.mdDoc "magic")
+lib.mkEnableOption "magic"
 # is like
 lib.mkOption {
   type = lib.types.bool;
   default = false;
   example = true;
-  description = lib.mdDoc "Whether to enable magic.";
+  description = "Whether to enable magic.";
 }
 ```
 :::
@@ -135,7 +132,7 @@ lib.mkOption {
   type = lib.types.package;
   default = pkgs.hello;
   defaultText = lib.literalExpression "pkgs.hello";
-  description = lib.mdDoc "The hello package to use.";
+  description = "The hello package to use.";
 }
 ```
 :::
@@ -153,7 +150,7 @@ lib.mkOption {
   default = pkgs.ghc;
   defaultText = lib.literalExpression "pkgs.ghc";
   example = lib.literalExpression "pkgs.haskell.packages.ghc92.ghc.withPackages (hkgs: [ hkgs.primes ])";
-  description = lib.mdDoc "The GHC package to use.";
+  description = "The GHC package to use.";
 }
 ```
 :::

nixos/lib/make-options-doc/default.nix

@@ -117,9 +117,7 @@
 # deprecated since 23.11.
 # TODO remove in a while.
 , allowDocBook ? false
-# whether lib.mdDoc is required for descriptions to be read as markdown.
-# deprecated since 23.11.
-# TODO remove in a while.
+# TODO remove in a while (see https://github.com/NixOS/nixpkgs/issues/300735)
 , markdownByDefault ? true
 }:
 

nixos/lib/systemd-types.nix

@@ -31,7 +31,6 @@ let
     ;
 
   inherit (lib)
-    mdDoc
     mkDefault
     mkDerivedConfig
     mkEnableOption
@@ -81,11 +80,11 @@ rec {
 
   initrdContents = attrsOf (submodule ({ config, options, name, ... }: {
     options = {
-      enable = mkEnableOption (mdDoc "copying of this file and symlinking it") // { default = true; };
+      enable = (mkEnableOption "copying of this file and symlinking it") // { default = true; };
 
       target = mkOption {
         type = path;
-        description = mdDoc ''
+        description = ''
           Path of the symlink.
         '';
         default = name;
@@ -94,12 +93,12 @@ rec {
       text = mkOption {
         default = null;
         type = nullOr lines;
-        description = mdDoc "Text of the file.";
+        description = "Text of the file.";
       };
 
       source = mkOption {
         type = path;
-        description = mdDoc "Path of the source file.";
+        description = "Path of the source file.";
       };
     };