libressl: fix loongarch64-linux build (#423618)

pkgs/development/libraries/libressl/default.nix

@@ -16,9 +16,10 @@ let
       version,
       hash,
       patches ? [ ],
+      postPatch ? "",
       knownVulnerabilities ? [ ],
     }:
-    stdenv.mkDerivation rec {
+    stdenv.mkDerivation {
       pname = "libressl";
       inherit version;
 
@@ -55,9 +56,11 @@ let
 
       inherit patches;
 
-      postPatch = ''
-        patchShebangs tests/
-      '';
+      postPatch =
+        ''
+          patchShebangs tests/
+        ''
+        + postPatch;
 
       doCheck = !(stdenv.hostPlatform.isPower64 || stdenv.hostPlatform.isRiscV);
       preCheck = ''
@@ -152,5 +155,16 @@ in
   libressl_4_1 = generic {
     version = "4.1.0";
     hash = "sha256-D3HBa9NL2qzNy5al2UpJIb+2EuxuDrp6gNiFTu/Yu2E=";
+    # Fixes build on loongarch64
+    # https://github.com/libressl/portable/pull/1184
+    postPatch = ''
+      mkdir -p include/arch/loongarch64
+      cp ${
+        fetchurl {
+          url = "https://github.com/libressl/portable/raw/refs/tags/v4.1.0/include/arch/loongarch64/opensslconf.h";
+          hash = "sha256-68dw5syUy1z6GadCMR4TR9+0UQX6Lw/CbPWvjHGAhgo=";
+        }
+      } include/arch/loongarch64/opensslconf.h
+    '';
   };
 }