build: add statically linked output

if only something like this was possible with wayland and others...

Cargo.toml

@@ -10,6 +10,9 @@ thiserror = "2.0.18"
 version = "1.30"
 default-features = false
 features = ["std", "float"]
+[dependencies.gmp-mpfr-sys]
+version = "*"
+features = ["force-cross"]
 
 [profile.release]
 lto = true

flake.nix

@@ -22,21 +22,29 @@
         cargoToml = fromTOML (builtins.readFile "${src}/Cargo.toml");
         name = cargoToml.package.name;
 
-        bin = pkgs.rustPlatform.buildRustPackage {
+        bin =
+          {
+            rustPlatform,
+            m4,
+          }:
+          rustPlatform.buildRustPackage {
             inherit name src;
 
             cargoLock.lockFile = "${src}/Cargo.lock";
 
-          nativeBuildInputs = with pkgs; [
+            nativeBuildInputs = [
               m4
             ];
           };
+
+        default = pkgs.callPackage bin { };
       in
       {
-        packages.default = bin;
+        packages.default = default;
+        packages.static = pkgs.pkgsStatic.callPackage bin { };
 
         devShells.default = pkgs.mkShell {
-          inputsFrom = [ bin ];
+          inputsFrom = [ default ];
 
           packages = with pkgs; [
             clippy