{
description = "A dev shell Nix flake for atlas";
inputs = {
flake-utils.url = "github:numtide/flake-utils";
nixpkgs.url = "github:nixos/nixpkgs/nixos-25.11";
crane.url = "github:ipetkov/crane";
rust-overlay = {
url = "github:oxalica/rust-overlay";
inputs.nixpkgs.follows = "nixpkgs";
};
};
outputs = {
self,
rust-overlay,
flake-utils,
nixpkgs,
...
}: let
in
flake-utils.lib.eachDefaultSystem
(
system: let
pkgs = import nixpkgs {
inherit system;
overlays = [rust-overlay.overlays.default];
};
in
with pkgs; rec
{
# Function to create a cross-build shell for a specific target
mkCrossBuildShell = targetSystem: let
# Define rust targets for each platform
rustTarget =
if targetSystem == "x86_64-linux"
then "x86_64-unknown-linux-musl"
else if targetSystem == "aarch64-linux"
then "aarch64-unknown-linux-musl"
else if targetSystem == "x86_64-darwin"
then "x86_64-apple-darwin"
else if targetSystem == "aarch64-darwin"
then "aarch64-apple-darwin"
else throw "Unsupported target system: ${targetSystem}";
isLinux = lib.hasSuffix "linux" targetSystem;
isDarwin = lib.hasSuffix "darwin" targetSystem;
# Import cross packages
# If target equals build system, don't set up cross-compilation
pkgsCross =
if targetSystem == system
then pkgs
else
import nixpkgs {
inherit system;
crossSystem = {
config =
if targetSystem == "x86_64-linux"
then "x86_64-unknown-linux-musl"
else if targetSystem == "aarch64-linux"
then "aarch64-unknown-linux-musl"
else if targetSystem == "x86_64-darwin"
then "x86_64-apple-darwin"
else if targetSystem == "aarch64-darwin"
then "aarch64-apple-darwin"
else throw "Unsupported target system: ${targetSystem}";
};
};
inherit (pkgs) lib;
# Use pkgsStatic for static libraries on all platforms
pkgsStatic = pkgsCross.pkgsStatic;
stdenv = pkgsStatic.libcxxStdenv;
# Rust toolchain
toolchain = pkgs.rust-bin.stable.latest.default.override {
targets = [rustTarget];
};
# Convert rust target to env var name (e.g., x86_64-unknown-linux-musl -> x86_64_unknown_linux_musl)
envVarName = builtins.replaceStrings ["-"] ["_"] rustTarget;
in
mkShell {
buildInputs =
[
]
++ lib.optionals stdenv.isDarwin [
pkgsStatic.libiconv
];
nativeBuildInputs = [
toolchain
];
CARGO_INCREMENTAL = 0; # disable incremental compilation
RUSTFLAGS =
# https://github.com/rust-lang/cargo/issues/4133
"-C linker=${stdenv.cc}/bin/${stdenv.cc.targetPrefix}ld"
+ (
if stdenv.isDarwin
then " -L ${pkgsStatic.libiconv.dev}/lib"
else " -C link-arg=-static -C target-feature=+crt-static"
);
# Static library configuration
LIBICONV_STATIC = lib.optionalString stdenv.isDarwin "1";
OPENSSL_STATIC = "1";
OPENSSL_LIB_DIR = "${pkgsStatic.openssl.out}/lib";
OPENSSL_INCLUDE_DIR = "${pkgsStatic.openssl.dev}/include";
shellHook = ''
echo "Cross-compilation shell for ${targetSystem}"
echo "Target: ${rustTarget}"
echo ""
${
if isLinux
then ''
echo "Building statically linked binaries with musl"
''
else if isDarwin
then ''
echo "Building for macOS (system libraries dynamic linking, everything else static)"
''
else ""
}
echo ""
echo "Key environment variables:"
echo " CARGO_BUILD_TARGET: $CARGO_BUILD_TARGET"
echo " RUSTFLAGS: $RUSTFLAGS"
echo " CARGO_INCREMENTAL: $CARGO_INCREMENTAL"
echo " RUSTC_WRAPPER: $RUSTC_WRAPPER"
echo " CC: $CC"
echo " CXX: $CXX"
echo " CC_${envVarName}: ''${CC_${envVarName}}"
echo " CXX_${envVarName}: ''${CXX_${envVarName}}"
echo ""
echo "To build binaries:"
echo " cargo build --release"
echo ""
echo "The resulting binaries will be in:"
echo " target/${rustTarget}/release/"
'';
# Cross-compilation environment variables
CARGO_BUILD_TARGET = rustTarget;
"CC_${envVarName}" = "${stdenv.cc}/bin/${stdenv.cc.targetPrefix}cc";
"CXX_${envVarName}" = "${stdenv.cc}/bin/${stdenv.cc.targetPrefix}c++";
"AR_${envVarName}" = "${stdenv.cc.bintools.bintools}/bin/${stdenv.cc.targetPrefix}ar";
};
# Create dev shells for each target
devShells = {
"crossBuildShell-x86_64-linux" = mkCrossBuildShell "x86_64-linux";
"crossBuildShell-aarch64-linux" = mkCrossBuildShell "aarch64-linux";
"crossBuildShell-x86_64-darwin" = mkCrossBuildShell "x86_64-darwin";
"crossBuildShell-aarch64-darwin" = mkCrossBuildShell "aarch64-darwin";
};
}
);
}
