Add darwin.nix and build instructions

README.md

@@ -48,6 +48,8 @@ LD_LIBRARY_PATH=. BEMENU_RENDERERS=. ./bemenu-run
 
 ## OSX
 
+### Homebrew
+
 ```sh
 # Make sure you have GNU Make and pkg-config installed
 brew install make pkg-config
@@ -59,6 +61,15 @@ PKG_CONFIG_PATH="/usr/local/opt/ncurses/lib/pkgconfig" sh build-osx.sh curses
 # Other than that, follow the normal build steps, but use `build-osx.sh` instead of make
 ```
 
+### Nix
+
+There is darwin.nix provided in this repo, you can install bemenu with it by running
+```sh
+nix-env -i -f darwin.nix
+```
+
+This installs only the curses backend.
+
 ## Dependencies
 
 - C compiler

darwin.nix

@@ -0,0 +1,31 @@
+{ pkgs ? import <nixpkgs> {} }:
+
+pkgs.stdenv.mkDerivation rec {
+  name = "bemenu";
+  src = ./.;
+  nativeBuildInputs = with pkgs; [ pkg-config scdoc ];
+  buildInputs = with pkgs; [ ncurses ];
+
+  postPatch = ''
+    substituteInPlace GNUmakefile --replace '-soname' '-install_name'
+  '';
+
+  makeFlags = ["PREFIX=$(out)"];
+  buildFlags = ["PREFIX=$(out)" "clients" "curses"];
+
+  # https://github.com/NixOS/nixpkgs/blob/master/pkgs/build-support/setup-hooks/fix-darwin-dylib-names.sh
+  # ^ does not handle .so files
+  postInstall = ''
+    so="$(find "$out/lib" -name "libbemenu.so.[0-9]" -print -quit)"
+    for f in "$out/bin/"*; do
+        install_name_tool -change "$(basename $so)" "$so" $f
+    done
+  '';
+
+  meta = with pkgs.lib; {
+    homepage = "https://github.com/Cloudef/bemenu";
+    description = "Dynamic menu library and client program inspired by dmenu";
+    license = licenses.gpl3Plus;
+    platforms = with platforms; darwin;
+  };
+}