Fix overwritting OPEN_HAB env

openhab.nix

@@ -10,19 +10,19 @@
   zip,
   unzip,
   stdenv,
-}:
-
-let
+  gnused,
+}: let
   version = builtins.readFile ./version;
   sha256 = builtins.readFile ./openhab.sha256;
-in stdenv.mkDerivation rec {
+in
+  stdenv.mkDerivation rec {
     inherit version;
     pname = "openhab";
     src = fetchurl {
       url = "https://github.com/openhab/openhab-distro/releases/download/${version}/openhab-${version}.tar.gz";
       inherit sha256;
     };
-    nativeBuildInputs = [ makeWrapper ];
+    nativeBuildInputs = [makeWrapper gnused];
     buildInputs = [bash];
     outputs = ["out"];
     extraPath = lib.makeBinPath [jdk-openhab gawk coreutils procps zip unzip];
@@ -66,6 +66,10 @@ in stdenv.mkDerivation rec {
       mv "$out/$exe".new "$out/$exe"
       done
 
+      # Fix OPENHAB_HOME overwritting
+      sed '6d' "$out/runtime/bin/oh_dir_layout" | sed '6i if [ -z ''${OPENHAB_HOME} ]; then\n\texport OPENHAB_HOME=`cd "$DIRNAME/../.."; pwd`\nfi' > "$out/runtime/bin/oh_dir_layout.new"
+      mv "$out/runtime/bin/oh_dir_layout.new" "$out/runtime/bin/oh_dir_layout"
+
       runHook postInstall
     '';
   }