From 657db64e51cceef71a0c910bad485dab00163843 Mon Sep 17 00:00:00 2001
From: Winter <winter@winter.cafe>
Date: Wed, 27 Mar 2024 17:14:45 -0400
Subject: [PATCH] Fix build on Nix 2.19+

Nix 2.19 introduced a change [0] that broke how we compile our libnixstore
bindings, which requires adding an additional include directory when
we compile them.

[0]: https://github.com/NixOS/nix/commit/b461cac21aa5b9127d230ed3f1a1ca8e8266fb60
---
 attic/build.rs | 3 +++
 crane.nix      | 6 ++++++
 flake.nix      | 3 +++
 package.nix    | 3 +++
 4 files changed, 15 insertions(+)

diff --git a/attic/build.rs b/attic/build.rs
index 3da0fed..da27f7d 100644
--- a/attic/build.rs
+++ b/attic/build.rs
@@ -24,6 +24,9 @@ fn build_bridge() {
         .flag("nix/config.h")
         .flag("-idirafter")
         .flag(hacky_include.path().to_str().unwrap())
+        // In Nix 2.19+, nix/args/root.hh depends on being able to #include "root.hh" (which is in its parent directory), for some reason
+        .flag("-I")
+        .flag(concat!(env!("NIX_INCLUDE_PATH"), "/nix"))
         .compile("nixbinding");
 
     println!("cargo:rerun-if-changed=src/nix_store/bindings");
diff --git a/crane.nix b/crane.nix
index 0c02289..4ec2827 100644
--- a/crane.nix
+++ b/crane.nix
@@ -62,6 +62,9 @@ let
 
     ATTIC_DISTRIBUTOR = "attic";
 
+    # See comment in `attic/build.rs`
+    NIX_INCLUDE_PATH = "${lib.getDev nix}/include";
+
     # See comment in `attic-tests`
     doCheck = false;
 
@@ -136,6 +139,9 @@ let
     checkPhaseCargoCommand = "cargoWithProfile test --no-run --message-format=json >cargo-test.json";
     doInstallCargoArtifacts = false;
 
+    # See comment in `attic/build.rs`
+    NIX_INCLUDE_PATH = "${lib.getDev nix}/include";
+
     installPhase = ''
       runHook preInstall
 
diff --git a/flake.nix b/flake.nix
index c8317d7..ea81e6f 100644
--- a/flake.nix
+++ b/flake.nix
@@ -130,6 +130,9 @@
         NIX_PATH = "nixpkgs=${pkgs.path}";
         RUST_SRC_PATH = "${pkgs.rustPlatform.rustcSrc}/library";
 
+        # See comment in `attic/build.rs`
+        NIX_INCLUDE_PATH = "${lib.getDev pkgs.nix}/include";
+
         ATTIC_DISTRIBUTOR = "dev";
       };
 
diff --git a/package.nix b/package.nix
index 1770f68..e40c765 100644
--- a/package.nix
+++ b/package.nix
@@ -49,6 +49,9 @@ in rustPlatform.buildRustPackage rec {
 
   ATTIC_DISTRIBUTOR = "attic";
 
+  # See comment in `attic/build.rs`
+  NIX_INCLUDE_PATH = "${lib.getDev nix}/include";
+
   # Recursive Nix is not stable yet
   doCheck = false;