nix-ld: restore module

flake.nix

@@ -38,6 +38,8 @@
       };
     };
 
+    nixosModules.nix-ld = import ./modules/nix-ld.nix {};
+
     devShells.default = pkgs.mkShell ({
       nativeBuildInputs = [
         pkgs.rustc

modules/nix-ld.nix

@@ -0,0 +1,77 @@
+{ pkgs, lib, config, ... }:
+let
+  cfg = config.programs.nix-ld.dev;
+
+  nix-ld-libraries = pkgs.buildEnv {
+    name = "lb-library-path";
+    pathsToLink = [ "/lib" ];
+    paths = map lib.getLib cfg.libraries;
+    # TODO make glibc here configurable?
+    postBuild = ''
+      ln -s ${pkgs.stdenv.cc.bintools.dynamicLinker} $out/share/nix-ld/lib/ld.so
+    '';
+    extraPrefix = "/share/nix-ld";
+    ignoreCollisions = true;
+  };
+
+  # We currently take all libraries from systemd and nix as the default.
+  # Is there a better list?
+  baseLibraries = with pkgs; [
+    zlib
+    zstd
+    stdenv.cc.cc
+    curl
+    openssl
+    attr
+    libssh
+    bzip2
+    libxml2
+    acl
+    libsodium
+    util-linux
+    xz
+    systemd
+  ];
+in
+{
+  meta.maintainers = [ lib.maintainers.mic92 ];
+
+
+  options.programs.nix-ld.dev = {
+    enable = lib.mkEnableOption (lib.mdDoc ''nix-ld, Documentation: <https://github.com/Mic92/nix-ld>'') // {
+      default = true;
+    };
+    package = lib.mkOption {
+      type = lib.types.package;
+      description = lib.mdDoc "The package to be used for nix-ld.";
+      default = pkgs.callPackage ../package.nix {};
+    };
+    libraries = lib.mkOption {
+      type = lib.types.listOf lib.types.package;
+      description = lib.mdDoc "Libraries that automatically become available to all programs. The default set includes common libraries.";
+      default = baseLibraries;
+      defaultText = lib.literalExpression "baseLibraries derived from systemd and nix dependencies.";
+    };
+  };
+
+  config = lib.mkIf config.programs.nix-ld.dev.enable {
+    assertions = [{ 
+      assertion = !config.programs.nix-ld.enable;
+      message = ''
+        nix-ld.dev cannot be enabled at the same time as nix-ld.
+      '';
+    }];
+
+    systemd.tmpfiles.packages = [ cfg.package ];
+
+    environment.systemPackages = [ nix-ld-libraries ];
+
+    environment.pathsToLink = [ "/share/nix-ld" ];
+
+    environment.variables = {
+      NIX_LD = "/run/current-system/sw/share/nix-ld/lib/ld.so";
+      NIX_LD_LIBRARY_PATH = "/run/current-system/sw/share/nix-ld/lib";
+    };
+  };
+}
+