I wanted to overlay nixpkgs.darwin.xcode in a devshell flake to include newer versions that are not yet available.
I started here which gave me some basic understanding, but simply adding a modified xcode.nix to an overlay like so
final: prev: {
darwin = prev.darwin // { inherit (prev.darwin.callPackage ./xcode.nix {}) xcode_15_2; };
helloxx = prev.hello;
}
doesn’t work (though the overlay works (tested with hellox))
It says: error: attribute 'xcode_15_2' missing.
Did I do something wrong in the override of the darwin attribute in the overlay?
I tried to take a shortcut and directly do the derivation inline in buildInputs with the requireFile expression etc. from xcode.nix for my specific xcode version, but couldn’t get it to work, probably due to making mistakes in the chaining of expressions.
As a workaround I can get xcode working in a devShell flake without overlay by just doing the appleSDK thing in the below flake.
{
description = "flutter shell";
inputs = {
# nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
flake-utils.url = "github:numtide/flake-utils";
};
outputs = { self, flake-utils, nixpkgs }:
flake-utils.lib.eachDefaultSystem (system: {
devShell =
let
pkgs = import nixpkgs {
inherit system;
config.allowUnfree = true;
overlays =
[ (import ./.nix/overlay) ]; # somehow doesn't work as expected?
};
inherit (pkgs) lib;
appleSDK =
if pkgs.stdenv.isDarwin then
(pkgs.darwin.callPackage ./.nix/overlay/xcode.nix { }).xcode_15_2
else
{ };
myllvm = pkgs.llvmPackages_15;
libs = with pkgs;
if stdenv.isLinux then [
atk
at-spi2-core.dev
dbus.dev
gtk3
pango
cairo
harfbuzz
gdk-pixbuf
glib # these are transitive but explicit here for the LD_LIBRARY_PATH
fontconfig
libdatrie
libselinux
libsepol
pcre
libthai
libxkbcommon
pcre2
util-linux.dev
xorg.libX11.dev
xorg.libXdmcp
xorg.libXtst
libappindicator.dev
libepoxy
libdeflate
gnome.zenity
] else if stdenv.isDarwin then
[
# libs needed for darwin
]
else
builtins.throw "Unsupported system (not Linux or Darwin)";
in
(pkgs.mkShell.override {
stdenv =
if pkgs.stdenv.isDarwin then
pkgs.stdenv
else
myllvm.stdenv;
}) {
nativeBuildInputs = with pkgs;
[ pkg-config ninja cmake dart flutter319 go envsubst ]
++ lib.optionals stdenv.isLinux [
myllvm.bintools # https://matklad.github.io/2022/03/14/rpath-or-why-lld-doesnt-work-on-nixos.html
];
buildInputs = libs ++ lib.optionals pkgs.stdenv.isLinux
(with myllvm; [ libcxxClang libunwind ])
++ lib.optionals pkgs.stdenv.isDarwin (with pkgs;
[
# this whole stuff is prepared as follows:
# https://github.com/NixOS/nixpkgs/blob/032324fd20e3be4124ffefd00da5bd66b0550e8c/pkgs/os-specific/darwin/xcode/default.nix#L23-L32
appleSDK
]);
shellHook =
if pkgs.stdenv.isDarwin then ''
# PATH=${appleSDK}/Contents/Developer/usr/bin:${appleSDK}/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin:$PATH
PATH=${appleSDK}/Contents/Developer/usr/bin:$PATH
SDKROOT=${appleSDK}/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk
'' else
"";
};
});
}
That even makes the flutter part of my project work.
BUT: depending on which PATH I set in the shellHook a go library I link into the flutter app won’t compile.
If I don’t set clang to the env’s Xcode (from Toolchain), I get
clang-16: error: cannot use 'cpp-output' output with multiple -arch options
and if I set the path I get
# runtime/cgo
_cgo_export.c:3:10: fatal error: 'stdlib.h' file not found
Anyway it seems that setting the paths for the stdenv by setting PATH in a shellHook is very hacky, is there a “natural” way to force the actually installed apple SDK?
(If I don’t set any paths I get the ancient SDK version 11). I guess that would more naturally solve library resolution?