To cross compiling a rust program for windows, run the following in a fresh directory:

nix flake init -t github:ipetkov/crane#cross-windows

Alternatively, if you have an existing project already, copy and paste the following flake.nix:

{ description = "Cross compiling a rust program for windows"; inputs = { nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable"; crane.url = "github:ipetkov/crane"; fenix = { url = "github:nix-community/fenix"; inputs.nixpkgs.follows = "nixpkgs"; }; flake-utils.url = "github:numtide/flake-utils"; }; outputs = { nixpkgs, crane, fenix, flake-utils, ... }: flake-utils.lib.eachDefaultSystem (system: let pkgs = nixpkgs.legacyPackages.${system}; toolchain = with fenix.packages.${system}; combine [ minimal.rustc minimal.cargo targets.x86_64-pc-windows-gnu.latest.rust-std ]; craneLib = (crane.mkLib pkgs).overrideToolchain toolchain; my-crate = craneLib.buildPackage { src = craneLib.cleanCargoSource ./.; strictDeps = true; doCheck = false; CARGO_BUILD_TARGET = "x86_64-pc-windows-gnu"; # fixes issues related to libring TARGET_CC = "${pkgs.pkgsCross.mingwW64.stdenv.cc}/bin/${pkgs.pkgsCross.mingwW64.stdenv.cc.targetPrefix}cc"; #fixes issues related to openssl OPENSSL_DIR = "${pkgs.openssl.dev}"; OPENSSL_LIB_DIR = "${pkgs.openssl.out}/lib"; OPENSSL_INCLUDE_DIR = "${pkgs.openssl.dev}/include/"; depsBuildBuild = with pkgs; [ pkgsCross.mingwW64.stdenv.cc pkgsCross.mingwW64.windows.pthreads ]; }; in { packages = { inherit my-crate; default = my-crate; }; checks = { inherit my-crate; }; } ); }