fix build against nix-meson

fix weird crash

flake.nix

@@ -9,12 +9,19 @@
   inputs.nix-github-actions.url = "github:nix-community/nix-github-actions";
   inputs.nix-github-actions.inputs.nixpkgs.follows = "nixpkgs";
 
+  inputs.nix.url = "github:NixOS/nix";
+  inputs.nix.inputs.nixpkgs.follows = "nixpkgs";
+  inputs.nix.inputs.flake-parts.follows = "";
+  inputs.nix.inputs.flake-compat.follows = "";
+  inputs.nix.inputs.git-hooks-nix.follows = "";
+  inputs.nix.inputs.nixpkgs-23-11.follows = "";
+  inputs.nix.inputs.nixpkgs-regression.follows = "";
+
   outputs =
     inputs@{ flake-parts, ... }:
     let
       inherit (inputs.nixpkgs) lib;
       inherit (inputs) self;
-      nixVersion = lib.fileContents ./.nix-version;
     in
     flake-parts.lib.mkFlake { inherit inputs; } {
       systems = inputs.nixpkgs.lib.systems.flakeExposed;
@@ -43,12 +50,17 @@
       };
 
       perSystem =
-        { pkgs, self', ... }:
+        {
+          inputs',
+          pkgs,
+          self',
+          ...
+        }:
         let
           drvArgs = {
             srcDir = self;
-            nix =
-              if nixVersion == "latest" then pkgs.nixVersions.latest else pkgs.nixVersions."nix_${nixVersion}";
+            nix = inputs'.nix.packages.nix;
+            #if nixVersion == "latest" then pkgs.nixVersions.latest else pkgs.nixVersions."nix_${nixVersion}";
           };
         in
         {

meson.build

@@ -4,11 +4,12 @@ project('nix-eval-jobs', 'cpp',
 )
 
 libcurl_dep = dependency('libcurl', required: true)
-nix_main_dep = dependency('nix-main', required: true)
-nix_store_dep = dependency('nix-store', required: true)
-nix_expr_dep = dependency('nix-expr', required: true)
 nix_cmd_dep = dependency('nix-cmd', required: true)
+nix_expr_dep = dependency('nix-expr', required: true)
+nix_fetchers_dep = dependency('nix-fetchers', required: true)
 nix_flake_dep = dependency('nix-flake', required: true)
+nix_main_dep = dependency('nix-main', required: true)
+nix_store_dep = dependency('nix-store', required: true)
 threads_dep = dependency('threads', required: true)
 nlohmann_json_dep = dependency('nlohmann_json', required: true)
 boost_dep = dependency('boost', required: true)

shell.nix

@@ -29,7 +29,7 @@ in
     (lib.hiPrio pkgs.llvmPackages_latest.clang-tools)
   ];
 
-  shellHook = lib.optionalString stdenv.isLinux ''
+  shellHook = lib.optionalString (stdenv.isLinux && nix ? debug) ''
     export NIX_DEBUG_INFO_DIRS="${pkgs.curl.debug}/lib/debug:${nix.debug}/lib/debug''${NIX_DEBUG_INFO_DIRS:+:$NIX_DEBUG_INFO_DIRS}"
   '';
 }

src/drv.cc

@@ -1,4 +1,3 @@
-#include <nix/config.h> // IWYU pragma: keep
 #include <nix/path-with-outputs.hh>
 #include <nix/store-api.hh>
 #include <nix/local-fs-store.hh>

src/meson.build

@@ -29,9 +29,18 @@ executable('nix-eval-jobs', src,
              nix_expr_dep,
              nix_cmd_dep,
              nix_flake_dep,
+             nix_fetchers_dep,
              boost_dep,
              nlohmann_json_dep,
              threads_dep
            ],
            install: true,
-           cpp_args: ['-std=c++2a', '--include', 'autotools-config.h'])
+           cpp_args: [
+             '-std=c++2a',
+             '--include', 'autotools-config.h',
+             '--include', 'nix/config-cmd.hh',
+             '--include', 'nix/config-expr.hh',
+             '--include', 'nix/config-main.hh',
+             '--include', 'nix/config-store.hh',
+             '--include', 'nix/config-util.hh',
+           ])

src/nix-eval-jobs.cc

@@ -1,4 +1,3 @@
-#include <nix/config.h> // IWYU pragma: keep
 // NOLINTBEGIN(modernize-deprecated-headers)
 // misc-include-cleaner wants these header rather than the C++ versions
 #include <signal.h>

src/worker.cc

@@ -1,5 +1,3 @@
-#include <nix/config.h> // IWYU pragma: keep
-
 // doesn't exist on macOS
 // IWYU pragma: no_include <bits/types/struct_rusage.h>