nixos/documentation: deprecate docbook option docs

following the plan in https://github.com/NixOS/nixpkgs/pull/189318#discussion_r961764451

also adds an activation script to print the warning during activation
instead of during build, otherwise folks using the new CLI that hides
build logs by default might never see the warning.

1 files changed, 10 insertions, 1 deletions

diff --git a/nixos/lib/make-options-doc/default.nix b/nixos/lib/make-options-doc/default.nix
index e2ed7bb7188..7595b66771a 100644
--- a/nixos/lib/make-options-doc/default.nix
+++ b/nixos/lib/make-options-doc/default.nix
@@ -139,9 +139,10 @@ in rec {
       dst=$out/share/doc/nixos
       mkdir -p $dst
 
+      TOUCH_IF_DB=$dst/.used-docbook \
       python ${./mergeJSON.py} \
         ${lib.optionalString warningsAreErrors "--warnings-are-errors"} \
-        ${lib.optionalString (! allowDocBook) "--error-on-docbook"} \
+        ${if allowDocBook then "--warn-on-docbook" else "--error-on-docbook"} \
         ${lib.optionalString markdownByDefault "--markdown-by-default"} \
         $baseJSON $options \
         > $dst/options.json
@@ -153,6 +154,14 @@ in rec {
       echo "file json-br $dst/options.json.br" >> $out/nix-support/hydra-build-products
     '';
 
+  optionsUsedDocbook = pkgs.runCommand "options-used-docbook" {} ''
+    if [ -e ${optionsJSON}/share/doc/nixos/.used-docbook ]; then
+      echo 1
+    else
+      echo 0
+    fi >"$out"
+  '';
+
   # Convert options.json into an XML file.
   # The actual generation of the xml file is done in nix purely for the convenience
   # of not having to generate the xml some other way