Fix jdk cross-compilation

flake.nix

@@ -7,8 +7,8 @@
     outputs = { flake-utils, nixpkgs, ... }:
     let
         overlay = final: prev: rec {
-            jdk-openhab = final.jdk11;
-            openhab = final.callPackage ./openhab.nix { inherit jdk-openhab; };
+            jdk-openhab = final.callPackage ./jdk.nix {};
+            openhab = final.callPackage ./openhab.nix { };
             openhab-addons = final.callPackage ./openhab-addons.nix {};
         };
         pkgs = system: import nixpkgs { inherit system; overlays = [ overlay ]; };

jdk.nix

@@ -0,0 +1,18 @@
+{ buildPlatform, hostPlatform, jdk11, which, zip, buildPackages }:
+
+if buildPlatform == hostPlatform
+then jdk11
+else (jdk11.override {
+    # libIDL does not compile in cross-compile scenarios.
+    enableGnome2 = false;
+}).overrideAttrs (old: {
+    # lol, nixpkgs can’t get pkgs right
+    # AUTOCONF = "${autoconf}/bin/autoconf";
+    nativeBuildInputs = old.nativeBuildInputs ++ [ which zip ];
+    depsBuildBuild = with buildPackages; [ stdenv.cc autoconf ];
+    configureFlags = old.configureFlags ++ [
+        "--with-jtreg=no"
+        "--disable-hotspot-gtest"
+        "--with-build-jdk=${buildPackages.jdk11}"
+    ];
+})