From dce01bd31b37c962039699f7dd306f0de7cd5b43 Mon Sep 17 00:00:00 2001
From: Brian Picciano <me@mediocregopher.com>
Date: Thu, 9 Nov 2023 23:52:07 +0100
Subject: [PATCH] Fix cross-compilation

---
 flake.nix | 37 ++++++++++++++++++++++---------------
 1 file changed, 22 insertions(+), 15 deletions(-)

diff --git a/flake.nix b/flake.nix
index 0e90f38..afad8bc 100644
--- a/flake.nix
+++ b/flake.nix
@@ -29,7 +29,7 @@
         supportedSystems
       );
 
-      mkPkgs = buildSystem: hostSystem: import nixpkgs {
+      mkPkgs = buildSystem: hostSystem: import nixpkgs ({
         system = buildSystem;
         overlays = [
           (import rust-overlay)
@@ -44,42 +44,49 @@
         # only set up the cross-compiling config if the target platform is
         # different.
         crossSystem.config = hostSystem;
-      });
+      }));
 
-      mkRustEnv = pkgs: {
+      mkRustEnv = crossPkgs: hostSystem: {
         OPENSSL_STATIC = "1";
-        OPENSSL_LIB_DIR = "${pkgs.pkgsStatic.openssl.out}/lib";
-        OPENSSL_INCLUDE_DIR = "${pkgs.pkgsStatic.openssl.dev}/include";
-        CARGO_BUILD_TARGET = buildTargetsBySystem.${pkgs.stdenv.hostPlatform.system};
-        CARGO_BUILD_RUSTFLAGS = "-C target-feature=+crt-static";
+        OPENSSL_LIB_DIR = "${crossPkgs.pkgsStatic.openssl.out}/lib";
+        OPENSSL_INCLUDE_DIR = "${crossPkgs.pkgsStatic.openssl.dev}/include";
+        CARGO_BUILD_TARGET = buildTargetsBySystem.${hostSystem};
+        CARGO_BUILD_RUSTFLAGS = [
+          "-C" "target-feature=+crt-static"
+          "-C" "linker=${crossPkgs.stdenv.cc}/bin/${crossPkgs.stdenv.cc.targetPrefix}cc"
+          "-C" "link-arg=-static"
+        ];
       };
+
     in
     {
       packages = eachCrossSystem (buildSystem: hostSystem: let
-        pkgs = mkPkgs buildSystem hostSystem;
+        pkgs = mkPkgs buildSystem buildSystem;
+        crossPkgs = mkPkgs buildSystem hostSystem;
         naersk-lib = pkgs.callPackage naersk {
           cargo = pkgs.rust-toolchain;
           rustc = pkgs.rust-toolchain;
         };
-        rustEnv = mkRustEnv pkgs;
+        rustEnv = mkRustEnv crossPkgs hostSystem;
       in
         naersk-lib.buildPackage ({
           src = ./.;
           doCheck = false;
-          nativeBuildInputs = [ pkgs.pkgsStatic.stdenv.cc ];
+          nativeBuildInputs = [ crossPkgs.pkgsStatic.stdenv.cc ];
         } // rustEnv)
       );
 
       devShells = eachCrossSystem (buildSystem: hostSystem: let
-        pkgs = mkPkgs buildSystem hostSystem;
-        rustEnv = mkRustEnv pkgs;
+        pkgs = mkPkgs buildSystem buildSystem;
+        crossPkgs = mkPkgs buildSystem hostSystem;
+        rustEnv = mkRustEnv crossPkgs hostSystem;
       in
         pkgs.mkShell ({
           nativeBuildInputs = [
-            pkgs.stdenv.cc
-            pkgs.openssl
-            pkgs.rust-toolchain
+            crossPkgs.stdenv.cc
+            crossPkgs.openssl
             pkgs.nmap # ncat
+            pkgs.rust-toolchain
           ];
           shellHook = ''
             export CARGO_HOME=$(pwd)/.cargo