The Manual HTML generation is done in bootstrapify-docbook.sh, and it doesn't have the nixos-release.tt in its pre-process chain, which will cause it to lack the current release for the stable manual link

The following diff includes the nix-release.tt file too, but probably isn't required.

diff --git a/bootstrapify-docbook.sh b/bootstrapify-docbook.sh
index f53788f..9475441 100755
--- a/bootstrapify-docbook.sh
+++ b/bootstrapify-docbook.sh
@@ -20,6 +20,7 @@ mkdir -p "$outDirTmp"
         xsltproc --nonet bootstrapify-docbook.xsl "$inDir/$fn" > "$outDirTmp/$fn.in"
         root=$(realpath --relative-to="$(pwd)" "$outDirTmp/$fn" | sed -e 's|[^/]||g' -e 's|/|../|g')
         tpage --pre_chomp --post_chomp \
+            --pre_process=nix-release.tt --pre_process=nixos-release.tt \
             --define root="${root}" \
             --pre_process=common.tt \
             > "$outDirTmp/$fn" <<EOF

Most of the file is soft-wrapped at around 75 chars. One simple newline would be welcome (imo).

diff --git a/nixos/support.tt b/nixos/support.tt
index b6b6763..5ccb27d 100644
--- a/nixos/support.tt
+++ b/nixos/support.tt
@@ -12,7 +12,8 @@
     configuration.nix</tt>. You can also <a href="options.html">search
     the list of options online</a>.</p>
 
-    <p>There is also <a href="[%nixosManual%]/unstable/">a version for the <strong>nixos-unstable</strong> channel</a>.</p>
+    <p>There is also <a href="[%nixosManual%]/unstable/">a version for the
+	<strong>nixos-unstable</strong> channel</a>.</p>
   </div>
 
   <div class="span4" id="discourse">

This will orphan a https://nixos.org/nixpkgs/manual/manual.html page, that seems to be un-indexed, but still will exist.

“But there's an rm!” or so I thought initially, but it's a no-op print of rm -rf; @echo is an unintuitive construct in Makefiles. (And I'm not targeting you, this seems borrowed from another target.)

What about fixing the rm -f? I'm not sure it's a good idea, this will, periodically (every twenty minutes or so) cause the manuals to briefly vanish from the server while they're being generated. Tried it locally and it's trivial to see it; this will end up confusing users, I think.

What should be done? Not sure. About the orphaned manual.html file? Maybe manually remove it. Should we mv manual.html index.html instead of symlinking to prevent unintended files to be present? Could we generate into a temp dir and as-atomically-as-possible pivot the manual to it instead of rm ing for the shortest amount of time the manuals?

Same comments about rm applies to the nixos manual, except there isn't a manual.html file there.