emilua: add setup hook that populates EMILUA_PATH

Signed-off-by: lucasew <lucas59356@gmail.com>

pkgs/development/interpreters/emilua/default.nix

@@ -110,6 +110,13 @@ stdenv.mkDerivation (self: {
     "--no-suite" "libpsx"
   ];
 
+  postInstall = ''
+    mkdir -p $out/nix-support
+    cp ${./setup-hook.sh} $out/nix-support/setup-hook
+    substituteInPlace $out/nix-support/setup-hook \
+      --replace @sitePackages@ "${self.passthru.sitePackages}"
+  '';
+
   passthru = {
     updateScript = gitUpdater {rev-prefix = "v";};
     inherit boost;

pkgs/development/interpreters/emilua/setup-hook.sh

@@ -0,0 +1,17 @@
+addEmiluaPath() {
+  addToSearchPathWithCustomDelimiter : EMILUA_PATH $1/@sitePackages@
+}
+
+toEmiluaPath() {
+    local paths="$1"
+    local result=
+    for i in $paths; do
+        p="$i/@sitePackages@"
+        result="${result}${result:+:}$p"
+    done
+    echo $result
+}
+
+if [ -z "${dontAddEmiluaPath:-}" ]; then
+    addEnvHooks "$hostOffset" addEmiluaPath
+fi