added nix config files to get builds working on nix/nixos

default.nix

@@ -0,0 +1,39 @@
+# To run this on nix/nixos, just run `nix-build` (or `nix build`) in the directory containing this file
+# and then run any executable in the result/bin directory,
+# e.g. `./result/bin/mpck`.
+# Or, if there is a corresponding flake.nix file and you have "flakes" enabled,
+# you can just run "nix run" and it will run the default executable ("mpck").
+# If you want to pass arguments to it or run a different executable, run it these ways:
+# nix run .#mpck -- arg  # put the arguments to be passed to the executable after the --
+
+{ pkgs ? import <nixpkgs> {}}:
+with pkgs;
+# fastStdenv.mkDerivation { # for faster running times (8-12%) BUT... nondeterministic builds :(
+fastStdenv.mkDerivation {
+  name = "checkmate";
+  src = ./.;
+
+  enableParallelBuilding = true;
+
+  # any dependencies/build tools needed at compilation/build time here
+  nativeBuildInputs = [ pkg-config gcc clang autoconf automake libtool ];
+
+  # any runtime dependencies here
+  buildInputs = [ ];
+
+  # the bash shell steps to build it
+  buildPhase = ''
+    ./autogen.sh
+    ./configure
+    make
+  '';
+
+  # for a generic copy of all compiled executables:
+  # cp $(find * -maxdepth 1 -executable -type f) $out/bin/
+  # to copy specific build outputs:
+  # cp keyconv oclvanitygen++ oclvanityminer vanitygen++ $out/bin/
+  installPhase = ''
+    mkdir -p $out/bin
+    cp mpck/mpck $out/bin/
+  '';
+}

flake.nix

@@ -0,0 +1,26 @@
+# If you run with Nix and you have "flakes" enabled,
+# you can just run "nix run" in this directory, and it will run the default executable here ("vanitygen++").
+# Also see the note(s) at the top of default.nix.
+{
+  inputs = {
+    nixpkgs.url = github:NixOS/nixpkgs/nixos-21.11;
+    # nixpkgs.url = "nixpkgs";
+    flake-utils.url = github:numtide/flake-utils;
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      rec {
+        packages.default = (import ./default.nix)
+          { pkgs = nixpkgs.legacyPackages.${system}; };
+
+        apps = rec {
+          default = checkmate;
+          checkmate = {
+            type = "app";
+            program = "${self.packages.${system}.default}/bin/mpck";
+          };
+        };
+      }
+    );
+}