From c12df57435e8c373a7d3bd4a8249a2a9ff51be48 Mon Sep 17 00:00:00 2001
From: Monson Shao <holymonson@gmail.com>
Date: Sat, 23 Jan 2021 21:49:13 +0800
Subject: [PATCH] darwin.apple-source-releases: implement headers check

---
 .../darwin/apple-source-releases/default.nix  | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/pkgs/os-specific/darwin/apple-source-releases/default.nix b/pkgs/os-specific/darwin/apple-source-releases/default.nix
index 014904ca24d..cb17d66e6a4 100644
--- a/pkgs/os-specific/darwin/apple-source-releases/default.nix
+++ b/pkgs/os-specific/darwin/apple-source-releases/default.nix
@@ -165,6 +165,25 @@ let
 
     enableParallelBuilding = true;
 
+    # In rare cases, APPLE may drop some headers quietly on new release.
+    doInstallCheck = attrs ? appleHeaders;
+    passAsFile = [ "appleHeaders" ];
+    installCheckPhase = ''
+      cd $out/include
+
+      result=$(diff -u "$appleHeadersPath" <(find * -type f | sort) --label "Listed in appleHeaders" --label "Found in \$out/include" || true)
+
+      if [ -z "$result" ]; then
+        echo "Apple header list is matched."
+      else
+        echo >&2 "\
+      Apple header list is inconsistent, please ensure no header file is unexpectedly dropped.
+      $result
+      "
+        exit 1
+      fi
+    '';
+
   } // attrs // {
     meta = (with lib; {
       platforms = platforms.darwin;