From 479d9fac7baa2d566e2224291c9a3f4af0586af2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rg=20Thalheim?= <joerg@thalheim.io>
Date: Sat, 10 Aug 2024 20:28:48 +0200
Subject: [PATCH] make updating cargo.lock more robust

* don't assume we have a nix flake registry instead take cargo from the
build
* set experimental flags
* apply patches to build
---
 nix_update/update.py                          | 31 ++++++++++++++++---
 .../cargo-lock-generate/simple/default.nix    |  6 +++-
 .../with-lockfile-metadata-path/default.nix   |  6 +++-
 3 files changed, 36 insertions(+), 7 deletions(-)

diff --git a/nix_update/update.py b/nix_update/update.py
index d31b0bc..02e3789 100644
--- a/nix_update/update.py
+++ b/nix_update/update.py
@@ -6,6 +6,7 @@
 import sys
 import tempfile
 import tomllib
+import textwrap
 from concurrent.futures import ThreadPoolExecutor
 from contextlib import contextmanager
 from os import path
@@ -258,15 +259,36 @@ def disable_copystat():
         finally:
             shutil.copystat = _orig
 
+    getSrcAndCargo = textwrap.dedent(f"""
+      {get_package(opts)}.overrideAttrs (old: {{
+        cargoDeps = null;
+        cargoVendorDir = ".";
+        postUnpack = ''
+          cp -pr --reflink=auto -- . $out
+          mkdir -p "$out/nix-support"
+          command -v cargo > $out/nix-support/cargo-bin || {{
+            echo "no cargo executable found in native build inputs" >&2
+            exit 1
+          }}
+          exit
+        '';
+        outputs = [ "out" ];
+        separateDebugInfo = false;
+      }})
+    """)
+
     res = run(
         [
             "nix",
+            "--extra-experimental-features",
+            "flakes nix-command",
             "build",
+            "-L",
             "--no-link",
             "--impure",
             "--print-out-paths",
             "--expr",
-            f"{get_package(opts)}.src",
+            getSrcAndCargo,
         ]
         + opts.extra_flags,
     )
@@ -276,12 +298,11 @@ def disable_copystat():
         with disable_copystat():
             shutil.copytree(src, tempdir, dirs_exist_ok=True, copy_function=shutil.copy)
 
+        cargo_bin = (src / "nix-support" / "cargo-bin").read_text().rstrip("\n")
+
         run(
             [
-                "nix",
-                "run",
-                "nixpkgs#cargo",
-                "--",
+                cargo_bin,
                 "generate-lockfile",
                 "--manifest-path",
                 f"{opts.lockfile_metadata_path}/Cargo.toml",
diff --git a/tests/testpkgs/cargo-lock-generate/simple/default.nix b/tests/testpkgs/cargo-lock-generate/simple/default.nix
index be641aa..c0729f0 100644
--- a/tests/testpkgs/cargo-lock-generate/simple/default.nix
+++ b/tests/testpkgs/cargo-lock-generate/simple/default.nix
@@ -1,7 +1,6 @@
 { python3Packages
 , rustPlatform
 , fetchFromGitHub
-,
 }:
 
 python3Packages.buildPythonPackage rec {
@@ -15,5 +14,10 @@ python3Packages.buildPythonPackage rec {
     hash = "sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=";
   };
 
+  nativeBuildInputs = [
+    rustPlatform.cargoSetupHook
+    rustPlatform.maturinBuildHook
+  ];
+
   cargoDeps = rustPlatform.importCargoLock { lockFile = ./Cargo.lock; };
 }
diff --git a/tests/testpkgs/cargo-lock-generate/with-lockfile-metadata-path/default.nix b/tests/testpkgs/cargo-lock-generate/with-lockfile-metadata-path/default.nix
index 1a85d85..b601016 100644
--- a/tests/testpkgs/cargo-lock-generate/with-lockfile-metadata-path/default.nix
+++ b/tests/testpkgs/cargo-lock-generate/with-lockfile-metadata-path/default.nix
@@ -1,7 +1,6 @@
 { python3Packages
 , rustPlatform
 , fetchFromGitHub
-,
 }:
 
 python3Packages.buildPythonPackage rec {
@@ -15,5 +14,10 @@ python3Packages.buildPythonPackage rec {
     hash = "sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=";
   };
 
+  nativeBuildInputs = [
+    rustPlatform.cargoSetupHook
+    rustPlatform.maturinBuildHook
+  ];
+
   cargoDeps = rustPlatform.importCargoLock { lockFile = ./Cargo.lock; };
 }