linux-manual: fix for Linux 6.19 (#490939)

pkgs/by-name/li/linux-manual/package.nix

@@ -2,7 +2,6 @@
   lib,
   stdenv,
   linuxPackages_latest,
-  perl,
   python3,
   man,
 }:
@@ -11,39 +10,35 @@ stdenv.mkDerivation {
   pname = "linux-manual";
   inherit (linuxPackages_latest.kernel) version src;
 
-  nativeBuildInputs = [
-    perl
-    python3
-  ];
+  nativeBuildInputs = [ python3 ];
   nativeInstallCheckInputs = [ man ];
 
   dontConfigure = true;
-  dontBuild = true;
   doInstallCheck = true;
 
   postPatch = ''
-    # Use scripts/kernel-doc.py here, not scripts/kernel-doc because
-    # patchShebangs skips symlinks
-
+    # Releases up to including 6.19.3 still use scripts/kernel-doc.py, but it
+    # has been moved to tools/docs with 7.0-rc1.
     patchShebangs --build \
-      scripts/kernel-doc.py \
-      scripts/split-man.pl
+      tools/docs \
+      scripts/kernel-doc.py
+  '';
+
+  buildPhase = ''
+    runHook preBuild
+
+    # avoid Makefile because it checks for unnecessary Python dependencies
+    KBUILD_BUILD_TIMESTAMP="$(date -u -d "@$SOURCE_DATE_EPOCH")" \
+    tools/docs/sphinx-build-wrapper mandocs
+
+    runHook postBuild
   '';
 
   installPhase = ''
     runHook preInstall
 
-    export mandir="$out/share/man/man9"
-    mkdir -p "$mandir"
-
-    KBUILD_BUILD_TIMESTAMP="$(date -u -d "@$SOURCE_DATE_EPOCH")" \
-    grep -F -l -Z \
-      --exclude-dir Documentation \
-      --exclude-dir tools \
-      -R '/**' \
-      | xargs -0 -n 256 -P "$NIX_BUILD_CORES" \
-        "$SHELL" -c '{ scripts/kernel-doc -man "$@" || :; } \
-          | scripts/split-man.pl "$mandir"' kernel-doc
+    mkdir -p "$out/share/man"
+    cp -r output/man "$out/share/man/man9"
 
     runHook postInstall
   '';